SERVICE MANUAL ELECTRICAL TROUBLESHOOTING

Transcription

1 SERVICE MNUL ELECTRICL TROUBLESHOOTING VOLUME 3 LL MODELS SERIL NUMBERS ND UP THE GRSSHOPPER COMPNY Moundridge, Kansas U.S.. (620) GRSSHOPPERMOWER.COM Price $12.00 Form Printed in U.S..

2 INTRODUCTION This manual has been developed to diagnose component failures only. It will not indicate a problem in the wiring or terminals. For example, if the troubleshooting guide indicates that the left steering switch is defective and replacing the left steering switch does not solve the problem; then you may have bad terminals or wiring to that switch. Consult the operator's manual wiring diagram for the specific year and model of the machine you are working on for troubleshooting. For further assistance, contact The Grasshopper Company, service department at (620) Copyright 2017, 2016 & 2015 by The Grasshopper Company. The following material is proprietary information. ll rights reserved. Reproduction or dissemination in any form by any means is prohibited, except by express written permission from The Grasshopper Company. 2

3 TBLE OF CONTENTS PGE INTRODUCTION 2 SWITCH FUNCTIONS 5-6 FUNCTION OF RELY 7 TROUBLESHOOTING CONTROL RELYS ll Kubota Gasoline Models...8 ll Kubota Diesel Models...8 Control Relay - ll Kubota Models...10 Circuit Board Diode Problems - ll Models...10 TESTING SFETY SYSTEM FOR PROPER OPERTION ll Briggs & Kohler Models...12 ll Kubota Models...13 BTTERY CHRGING SYSTEM ll Briggs Models & Kohler Models excluding Kohler EFI Models...14 ll Kubota Models with Smooth lternators ll Kubota Models with luminum/finned lternators...16 ENGINE WILL NOT CRNK 124, 126, 226V and 616T Series Models Kohler, 200 Series Models except 226V, ll Briggs Big Block Models, 620T & 623T Models and all 700 Kohler Models ll Kubota Models ENGINE WILL CRNK, BUT NOT STRT ll Briggs & Kohler Models...24 ll Kubota Gasoline Models...25 ll Kubota Diesel Models except those with D902 Engines Kubota Diesel Models with D902 Engines...27 ENGINE STRTS, BUT DIES WHEN STEERING LEVERS RE BROUGHT IN OR PTO SWITCH IS ENGGED ll Models...28 ENGINE STRTS, BUT DIES WHEN KEY SWITCH IS RELESED ll Kubota Diesel Models except those with D902 Engines Kubota Diesel Models with D902 Engines...32 Briggs & Kohler Models (continued)

4 TBLE OF CONTENTS (CONTINUED) ENGINE STRTS ND RUNS, BUT WILL NOT SHUT OFF Kubota Diesel Models with D902 Engines TROUBLESHOOTING PTO CLUTCH ll Models except Kubota...36 ll Kubota Models...37 cceptable Clutch Resistance Range in Ohms...38 High Temperature Clutch Cutout Wiring...39 TROUBLESHOOTING ELECTRIC LIFT Electric Lift Does t Operate Wiring Diagram...44 HYDRULIC LIFT DOES NOT WORK Hydraulic Dozer Electrical Troubleshooting...45 One Piece Tilt Switch/Delay Timer Style JOYSTICK WIRING TROUBLESHOOTING Joystick Wiring Troubleshooting - Total Loss of Motion...48 Joystick Wiring Troubleshooting - Loss of Motion in One Direction...49 TRCTOR CCESSORY HRNESS TROUBLESHOOTING ll Models

5 SWITCH FUNCTIONS Ignition switch, part no (ll Briggs, Kawasaki & Kohler Models). M Magneto terminal. S Starter terminal. B Battery terminal. L Lights, accessory terminal. G Ground terminal. Ignition switch, part no (ll Kubota Models). 30 Battery terminal. 50 Starter terminal. C ccessory terminal. 17 Glow plug terminal (Diesel only). 19 Glow plug indicator terminal (Diesel only). NC NO NC NO RELESED DEPRESSED Brake switch, part no NC (normally closed) - means that the contact is closed and current will fl ow between these two terminals. When the button is depressed, these two terminals become open. NO (normally open) - means that the contact is open with the switch mechanism released. When the button is depressed, these two terminals become closed. The dotted line indicates an electrical connection between the two terminal posts. 5

6 SWITCH FUNCTIONS Left and right steering switch, part no NC (normally closed) - means that the contact is closed with the switch mechanism released. The contact position is reversed when the switch lever is depressed. NO (normally open) - means that the contact is open with the switch mechanism released. The contact position is reversed when the switch lever is depressed. The dotted line indicates an electrical connection between the two terminal posts. PTO switch, part no The dotted line indicates an electrical connection between the two terminal posts. Seat switch, part no The dotted line indicates an electrical connection between the two terminal posts. 6

7 FUNCTION OF RELY a NON-ENERGIZED NON-ENERGIZED - Means that terminal 30 and terminal 87a are connected when the relay is not energized ENERGIZED a ENERGIZED - Means that terminal 30 and terminal 87 are connected when the relay is energized CONTROL RELY OPERTION FRONT MOUNT MID MOUNT B C D E Run Relay - ccessory Start Relay High Temp - Output from the Temp Gauge Latch Up Relay High Temp - Opens Clutch Circuit Universal Harness - Opens Clutch Circuit Run Relay - ccessory Start Relay High Temp - Output from the Temp Gauge Latch Up Relay High Temp - Opens Clutch Circuit Switches +12 Volts to Deck Height Pump 7

8 TROUBLESHOOTING CONTROL RELYS LL KUBOT GSOLINE MODELS 1. Control relay - inspection.. Control relay has 2 red wires, 2 black wires, 1 yellow wire and 2 green wires in the relay socket. B. Control relay B has 3 blue wires and 1 green wire in the relay socket. 2. ssuming the main fuse, PTO fuse, ignition fuse are good, failure of control relay or associated wiring will be evidenced by the following three symptoms:. PTO clutch will not engage. B. Hourmeter will not run. C. Ignition coil will not have voltage on the positive terminal* 3. ssuming the start fuse is good, failure of control relay B or associated wiring will result in starter solenoid not engaging; thus the starter motor will not operate. * (On 432 and 932, the plug which leads to igniter assembly will not have voltage). Figure 1 To main fuse To pad of PC board Red w/white Yellow w/brown +12 volts with key switch in RUN position Black LL KUBOT DIESEL MODELS 1. Control relay - inspection.. Control relay has 2 red wires, 1 black wire, 1 yellow wire and 1 green wire in the relay socket. B. Control relay B has 3 blue wires and 1 green wire in the relay socket. 2. ssuming the main fuse, PTO fuse, ignition fuse are good, failure of control relay or associated wiring will be evidenced by the following three symptoms:. PTO clutch will not engage. B. Hourmeter will not run. C. Fuel solenoid will pull in but not hold. 3. ssuming the start fuse is good, failure of control relay B or associated wiring will result in starter solenoid not engaging; thus the starter motor will not operate. To pad M of PC board This wire goes to ground when: 1. Driver on seat and parking brake released, 2. or PTO off, both steering levers out, 3. or both of the above. Relay C To G terminal on Voltmeter Gauge Figure 2 Green Green +12 volts with relay is energized Red Black To I terminal on Voltmeter Gauge To PTO fuse & ignition fuse Blue To start fuse Run Relay - ccessory To pad R of PC board Green w/yellow +12 volts with key switch in STRT position This wire goes to ground with steering levers out and PTO off +12 volts with relay B is energized Blue 8 Starter solenoid Start Relay

9 Temp Light This wire goes to ground when the temp gauge needle gets into the red. Purple Purple C Black To Relay D +12 volts with key in the RUN position Relay D Purple Black To Relay Figure 3 Relay Green This is a ground wire Green To Pad G of PC Board High Temp Relay - Temp. Gauge Circuit To Pad P of PC Board Brown +12 volts with PTO Switch on +12 volts with key in the RUN position To Temp Gauge Purple Black To Relay C To Relay C Purple D Black To Pad M on PC Board To Relay E Brown This wire goes to ground when the temp gauge needle gets into the red. +12 volts with PTO Switch on High Temp Relay - Clutch Circuit Figure volts with PTO switch on To Universal Harness This is a ground wire Green E Brown Brown To PTO Switch To Universal Harness Figure 5 To Relay D Brown +12 volts with PTO Switch on Switched +12 volts from Universal Harness Universal Harness Relay - Clutch Circuit 9

10 CONTROL RELY - LL KUBOT MODELS ssuming a normal diode on the circuit, board, relay B is affected by a problem in the circuit containing the PTO switch, and left and right steering switches. ssuming a normal diode on the circuit board, relay is affected by a problem in the circuit containing the PTO switch, and left and right steering switches. It is also affected by a problem in the circuit containing the parking brake switch and seat switch. FUNCTION OF DIODE The function of a diode is to allow an electric current to pass in one direction (called the diode's forward direction). diode can be referred as an electronic check valve. CIRCUIT BORD DIODE PROBLEMS - LL MODELS Refer to the illustration below (fi gure 7) to locate the diode on the circuit board between pad R and. Open Diode n open diode will result in the following symptoms: ssuming steering levers out and PTO switch off, engine can be cranked and started only with driver on the seat and the parking brake in the 'OFF' position. If driver gets off of the seat or puts parking brake to the 'ON' position, the engine will die. Shorted Diode SYMBOLS USED ON WIRING DIGRMS Figure 6 Symbol for a diode. The arrow indicates the current flow. Current will not flow in the other direction if the diode is working properly. ssuming an operator on the seat and parking brake is 'OFF', engine can be cranked and started with PTO switch in the 'ON' position or steering levers in. Circuit Board with Diode R Figure 7 10

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12 TESTING SFETY SYSTEM FOR PROPER OPERTION Steering levers out, PTO switch 'OFF'. If engine starts, all of the above switches are functioning in their closed position. Turn engine 'OFF'. Does engine crank with only left steering lever 'IN'? Does engine crank with only right steering lever 'IN'? Does engine crank with only the PTO switch turned 'ON'? djust or replace left steering switch. djust or replace right steering switch. Replace PTO switch. LL BRIGGS MODELS LL KOHLER MODELS tes: Proper operation of the safety system indicates that: 1. To start the engine, both steering levers must be out, and the PTO switch must be off. 2. With the engine running and the operator off the seat, the engine will die if either steering lever is brought in or the PTO switch is turned on. 3. The engine will also die if the operator gets off the seat with either steering lever in or the PTO switch turned on. 4. The engine will die if the steering levers are brought in with the parking brake on. Steering levers out, PTO switch 'OFF', operator OFF seat, parking brake 'OFF' and engine running. Does engine die when one or both steering levers are brought 'IN'? Steering levers out, PTO switch 'OFF', operator ON seat, parking brake 'ON' and engine running. Does engine die when one or both steering levers are brought 'IN'? ll safety systems are functioning properly. Replace relay. Replace brake switch. 12

13 TESTING SFETY SYSTEM FOR PROPER OPERTION LL KUBOT MODELS Steering levers out, PTO switch 'OFF', parking brake 'OFF', operator OFF seat and engine running. tes: Proper operation of the safety system indicates that: 1. To start the engine, both steering levers must be out, and the PTO switch must be off. The engine will start with the operator on or off the seat and the parking brake either on or off. 2. With the engine running and the operator off the seat, the engine will die if either steering lever is brought in or the PTO switch is turned on. 3. The engine will also die if the operator gets off the seat with either steering lever in or the PTO switch turned on. 4. The engine will die if the steering levers are brought in with the parking brake on. Does engine die when left steering lever is brought 'IN'? Does engine die when right steering lever is brought 'IN'? Does engine die when the PTO switch is turned 'ON'? To djust or replace left steering switch. djust or replace right steering switch. Replace PTO switch. Steering levers out, PTO switch 'OFF', parking brake 'ON', operator ON seat and engine running. Does engine die when steering levers are brought 'IN'? Replace brake switch. Steering levers in, PTO switch 'OFF', parking brake 'OFF', operator ON seat and engine running. Does engine die when operator raises up off the seat? Replace seat switch. ll safety systems are functioning properly. 13

14 BTTERY CHRGING SYSTEM Engine is not running. ttach DC voltmeter to negative and positive posts of battery. Does voltmeter read 12.5 DC volts or above? Test and recharge battery. Battery is in good condition. LL BRIGGS MODELS *LL KOHLER MODELS EXCLUDING KOHLER EFI MODELS tes: 1. Voltage tests are performed with a DC/C voltmeter. 2. Tests are performed after regulator fuse is checked. 3. C voltage tests are performed with engine at 3600 rpm. Start engine and observe battery voltage at full throttle. Is voltage at battery between 13 and 14.7 DC volts? at the B+ teminal of the regulator - rectifier. See diagram for location. Fig 8 Charging system is functioning properly. Disconnect regulator - rectifier plug. Place C voltmeter across C Terminals in plug and read voltage. Fig 8 *NOTE: For a battery charging problem with a Kohler EFI engine, consult the engine repair manual. Problem is in supply wire from regulator fuse to regulator rectifier. Does voltage read less than 28 volts C with engine running? If C voltage measures more than 28 volts replace regulator - rectifier. Service stator. For more detailed testing consult the engine repair manual. B+ C C B+ C Red Yellow Yellow White Purple White Briggs Regulator Kohler Regulator Plug Figure 8 14

15 BTTERY CHRGING SYSTEM LL KUBOT MODELS WITH SMOOTH LTERNTORS W/TWO WIRES Engine is not running. ttach DC voltmeter to negative and positive posts of battery. tes: 1. Voltage tests are performed with a DC/C voltmeter. 2. Tests are performed after regulator fuse is checked. 3. C voltage tests are performed with engine at full RPM. Does voltmeter read 12.2 DC volts or above? Battery is in good condition. Test and recharge battery. Start engine and observe battery voltage at full throttle. Is voltage at battery between 13 and 14.7 DC volts? Charging system is functioning properly. Does C voltage appear between the 2 blue wires from alternator?. 10 volts* at idle? B. 36 volts* C at full throttle? Does DC voltage appear on white wire to voltage regulator plug to ground? Does green wire on the regulator plug between the two blue wires show ground when tested to battery positive? Replace alternator. Check ground connection. on terminal C of ignition switch to ground? Check ignition switch for continuity from terminal C to terminal 30. Rev Check white wire and terminals from terminal C of ignition switch to voltage regulator. 15 Is voltage at red wire of voltage regulator DC volts to ground? Check red wire, regulator fuse and terminals from terminal 30 of ignition switch to voltage regulator. Replace voltage regulator. *voltage may vary + or - 3 volts.

16 BTTERY CHRGING SYSTEM LL KUBOT MODELS WITH LUMINUM/FINNED LTERNTORS Engine is not running. tes: 1. Tests are performed after regulator fuse is checked. 2. Set voltmeter to DC voltage for testing on this page. ttach voltmeter to negative and positive posts of battery. Does voltmeter read 12.5 volts or above? Battery is in good condition. Test and recharge battery. Start engine and observe battery voltage at full throttle. Is voltage at battery between 13 and 14.7 volts? Charging system is functioning properly. Test for voltage at red wire to alternator Problem is with In-line Fuse Wire Does voltage appear on white wire to alternator with ignition key in the run position? Check connections of white wire from alternator to the circuit board. Does green wire at alternator show ground when tested to battery positive? Check ground connections. Service lternator Regulator ssembly 16

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18 ENGINE WILL NOT CRNK Test battery for condition and charge. Steering levers out, PTO switch 'OFF'. Voltage tests are performed with a voltmeter or test light to battery ground. Key switch is in 'STRT' position for each test. 124 & 126 BRIGGS 226V BRIGGS 616T BRIGGS tes: 1. Voltage tests are performed with a DC voltmeter. Warning! Before starting test, remove blue wire from starter solenoid to prevent accidental cranking of engine while testing. Reconnect this blue wire upon completion of the test. from terminal 'C' of start fuse? (See Figure 9) from terminal 'D' of start fuse? Replace start fuse. If there is voltage at terminal 'D' of start fuse, there should also be voltage on blue wire at starter solenoid. To continues on next page Problem is the key switch or the power to the key switch. Figure 9 18

19 continued from previous page ENGINE WILL NOT CRNK (CONTINUED) Key switch is in 'OFF' position for each test. You are now testing a ground circuit. ll tests will be to the battery positive side. 124 & 126 BRIGGS 226V BRIGGS 616T BRIGGS Does the yellow wire at starter solenoid show ground when tested? Check starter solenoid. Problem could be starter solenoid or starter. Does either yellow wire on PTO switch show ground when tested? Do either yellow wires on right steering switch show ground when tested? Do either yellow wires on left steering switch show ground when tested? Check ground junction with green wires on engine. Replace PTO switch. Right steering switch is defective or out of adjustment. Left steering switch is defective or out of adjustment. Fuse Block Test Points Fuse block styles will vary. Be sure you are checking designated fuse. B DC FE HG 30 REGULTOR FUSE 7.5 STRT FUSE 10 PTO FUSE 7.5 LIGHT FUSE Figure 10 Rev

20 ENGINE WILL NOT CRNK Test battery for condition and charge. OK Steering levers out, PTO switch 'OFF'. Voltage test is performed with a voltmeter or test light to battery ground. Key switch is in 'STRT' position for each test. 125 & 225V KOHLER LL 200 SERIES MODELS EXCEPT 226V 329B, 335B, 729BT 6 & 735BT 6 BRIGGS BIG BLOCK MODELS 620T & 623T KOHLER LL 700 SERIES KOHLER MODELS tes: amp MSTER fuse is present on all 700 series except 723T. This fuse is in the upper level of fuse block on right side of tractor frame next to seat. Voltage will not reach the key switch if this fuse is blown. 2. Do not forget to plug starter relay back in when fi nished testing. Warning! Before starting test, remove blue wire from starter solenoid to prevent accidental cranking of engine while testing. Reconnect this blue wire upon completion of the test. Does voltage appear from terminal 'C' of start fuse? Does voltage appear from terminal 'D' of start fuse? Does voltage appear on terminal 85 of starter relay? Does voltage appear on terminal 87 (inline fuse wire) of starter relay? To continues on next page Problem is the key switch or the power to the key switch. Replace start fuse. Check wires from start fuse to starter relay. Check 30 amp in-line fuse in wire between starter relay and starter solenoid. LL EXCEPT 125 & 225V 125 & 225V RED KEY SWITCH (in start position) BLUE STRT FUSE BLUE RED INLINE S L FUSEHOLDER 87 M 86 87a 85 B G 30 PTO SWITCH (PTO OFF) STEERING SWITCHES RIGHT LEFT (Steering levers out) RED KEY SWITCH (in start position) BLUE STRT FUSE BLUE RED INLINE FUSEHOLDER S 87 L 86 87a 85 M B G 30 PTO SWITCH (PTO OFF) STEERING SWITCHES RIGHT LEFT (Steering levers out) RED STRTER BLUE STRTER RELY YELLOW YELLOW RT STR YELLOW LT STR GREEN / YELLOW RED STRTER BLUE STRTER RELY YELLOW YELLOW RT STR YELLOW LT STR GREEN / YELLOW Figure 11 Figure Rev

21 ENGINE WILL NOT CRNK (CONTINUED) continued from previous page on terminal 30 of starter relay? Key switch is in 'OFF' position for each test. You are now testing a ground circuit. ll tests will be to the battery positive side. Check starter solenoid. Problem could be starter solenoid or starter. 125 & 225V KOHLER LL 200 SERIES MODELS EXCEPT 226V 329B, 335B, 729BT 6 & 735BT 6 BRIGGS BIG BLOCK MODELS 620T & 623T KOHLER LL 700 SERIES KOHLER MODELS 700 Series Kohler Models except 723T Fuse Block Test Points LIGHT/UX FUSE MP. PTO FUSE - 10 MP. STRT FUSE - 30 MP. Remove the starter relay. It is located on the inside of the frame, on the left side of the engine on Kohler models. Does the yellow wire without the in-line fuse show ground when tested? Replace the starter relay. G H B E F C D DC B FE MSTER FUSE - 30 MP. REGULTOR FUSE - 30 MP. CCESSORY FUSE UNIVERSL HRNESS FUSE - 10 MP CCESSORY FUSE Figure 13 Fuse block styles will vary. Be sure you are checking designated fuse. HG Does either yellow wire on PTO switch show ground when tested? Does either yellow wire on right steering switch show ground when tested? Does either yellow wire on left steering switch show ground when tested? Check ground at engine. Replace PTO switch. Right steering switch is defective or out of adjustment. Left steering switch is defective or out of adjustment. 30 If all safety switches are correct, terminal 86 is grounded. Terminal 87 is 12 volts. Terminal 85 is +12 volts when key switch is in STRT position. Terminal 30 is +12 volts whenrelay is energized. Yellow Wire 87 87a REGULTOR FUSE 7.5 STRT FUSE 125 & ll 200 Series Models (Regulator fuse absent on 125 & 225V) Figure 14 Blue Wire 10 PTO FUSE 7.5 LIGHT FUSE Starter Relay Testing To pad T of circuit board Fuse holder To battery 30 terminal of starter Blue Wire Fuse clip to regulator fuse To pad S of circuit board To input terminal of starter Figure 15 Rev

22 ENGINE WILL NOT CRNK LL KUBOT MODELS Test battery for condition and charge. OK Steering levers out, PTO switch 'OFF'. Voltage test is performed with a voltmeter or test light to battery ground. Key switch is in 'STRT' position for each test. G H I J STRT FUSE - 30 MP. IGNITION FUSE MP. PTO FUSE - 10 MP. MIN FUSE - 15 MP. B CCESSORY FUSE - 10MP. MSTER FUSE - 30 MP. te: Check 30 amp MSTER fuse in lower level of fuse block on right side of tractor frame next to seat. Voltage will not reach key switch if this fuse is blown. Warning! Before starting test, remove blue wire from starter solenoid to prevent accidental cranking of engine while testing. Reconnect this blue wire upon completion of the test. from terminal 'I' of start fuse? from terminal 'J' of start fuse? on blue wire at starter solenoid? Check starter solenoid. Problem could be starter solenoid or starter. Problem is the key switch or the power to the key switch. Replace start fuse. To continues on next page - ; I J= H JF I EJE / / J H E C L H I K J / , * 7 - # ' ) + %! 5 6 ) * 7 - * 7 - * ) ; ) ; * / ; - 9 ; - 9 Figure Rev

23 ENGINE WILL NOT CRNK (CONTINUED) continued from previous page LL KUBOT MODELS Key switch is in 'OFF' position for each test. You are now testing a ground circuit. ll tests will be to the battery positive side. Remove relay 'B'. It is the relay with 3 blue wires and 1 yellow wire in the plug. Does the green/ yellow wire on the plug of relay 'B' show ground when tested? Replace relay 'B'. Relay B Do both wires on left steering switch show ground when tested? Do both yellow wires on right steering switch show ground when tested? Replace PTO switch. Before replacing the steering switch, check adjustment. If it does not click when steering levers are moved in and out adjust the switch. Replace left steering switch. Before replacing the steering switch, check adjustment. If it does not click when steering levers are moved in and out adjust the switch. Replace right steering switch. Fuse Block Test Points Fuse block styles will vary. Be sure you are checking designated fuse. G H IGNITION FUSE MP. PTO FUSE - 10 MP. MIN FUSE - 15 MP. B CCESSORY FUSE - 10MP. Figure 17 I J MSTER FUSE - 30 MP. STRT FUSE - 30 MP. Figure 18 Rev

24 ENGINE WILL CRNK, BUT NOT STRT LL BRIGGS MODELS LL KOHLER MODELS If engine cranks, but will not run; the safety switches are functioning properly. tes: 1. Tests are performed after LIGHT/UX fuse has been checked on all models. Test engine for spark. Does spark occur at spark plug? Disconnect yellow safety wire* from engine and retest. Does spark now occur at spark plug? Reconnect yellow safety wire. There is an engine ignition related problem. Consult engine repair manual. Check for fuel system problem or engine failure. Reconnect yellow safety wire. Replace safety relay in console. Use part number relay for all 100, 200, 300 & 600 tractors. Use part number relay for 700 series tractors with serial number & below. Use part number relay for 700 series tractors with serial number & above. * Briggs engine excluding Briggs Big Block: Single yellow wire on left side of engine. Kohler & Briggs Big Block engine: Disconnect plug on left side of engine. Using a small screwdriver, release the lock tab on yellow wire in tractor side plug and remove wire. Reconnect the plug. Warning! With the yellow wire disconnected from the engine, all safety functions and the key switch will be inoperable in their ability to shutoff the engine. This step is performed for test purposes only. Under no conditions should the PTO be turned ON or the machine be driven with the yellow wire disconnected! lways reconnect the yellow wire to the engine after this test. 24

25 ENGINE WILL CRNK, BUT NOT STRT Steering levers out, PTO switch 'OFF'. Voltage tests are performed with a voltmeter or test light to battery ground (negative post). Key switch is in 'RUN' position for each test until otherwise noted. from black wire on positive terminal of ignition coil to ground? * Problem is in ignition coil or distributor. Consult Kubota engine manual for repair. LL KUBOT GSOLINE MODELS tes: 1. ll tests are made with wires in place on their respective switches. 2. Refer to fuse block diagram for terminal locations. 3. Refer to Troubleshooting Control Relays for information on the diode and control relays. 4. If engine will crank, control relay B is functioning properly. This means that the PTO switch, right steering switch and left steering switch are functioning properly. Replace control relay. from terminal 'G' of ignition fuse to ground? from terminal '' of main fuse to ground? Replace ignition fuse. from terminal 'B' of main fuse to ground? Fuse Block Test Points Fuse block styles will vary. Be sure you are checking designated fuse. G H IGNITION FUSE MP. PTO FUSE - 10 MP. MIN FUSE - 15 MP. B CCESSORY FUSE - 10MP. from terminal 30 (battery) of key switch to ground? Replace main fuse. I J MSTER FUSE - 30 MP. STRT FUSE - 30 MP. Figure 19 Test battery. - ; H K F I EJE Replace key switch. 4 -, ) * ) + * For models 329/729 & 432/932, test for voltage at red wire in white 2-way plug located directly below carburetor on engine. 4 -, # ' ) + %! 4 -, ) ; ) ; - 9 * ). - 6 ; / , * ) + 1/ Figure 20 25

26 ENGINE WILL CRNK, BUT NOT STRT Steering levers out, PTO switch 'OFF'. Voltage tests are performed with a voltmeter or test light to battery ground (negative post). Key switch is held in 'STRT' position for each test until otherwise noted. LL KUBOT DIESEL MODELS EXCEPT THOSE WITH D902 ENGINES tes: 1. ll tests are made with wires in place on their respective switches. 2. Refer to fuse block diagram for terminal locations. 3. Refer to Troubleshooting Control Relays for information on the diode and control relays. 4. If engine will crank, control relay B is functioning properly. This means that the PTO switch, right steering switch and left steering switch are functioning properly. from 'PULL' wire of the fuel solenoid to ground? Test in-line fuse and fuse holder. Does fuel solenoid engage while cranking? Key switch is OFF during each test. Does 'COMM' terminal of fuel solenoid show ground? Repair ground connection to 'COMM' terminal of fuel solenoid. Problem This is an is in engine ignition coil related or distributor. problem. Consult Kubota engine engine repair manual for further repair. information. Does resistance measure approximately.2 to.5 ohms from 'PULL' terminal to 'COMM' terminal of fuel solenoid? Replace fuel solenoid. Fuel solenoid linkage is binding or sticking. + - BTTERY CBLE C RED RED MIN FUSE RED / WHITE KEY SWITCH RED / WHITE (In run position) RELY YELLOW / BROWN TO SFETY SWITCHES SOLENOID FUSE RED 4 3 FUEL SOLENOID MODULE GREEN WHITE HOLD PULL COMM FUEL SOLENOID STRTER IN-LINE FUSEHOLDER Figure 21 26

27 ENGINE WILL CRNK, BUT NOT STRT If engine will crank, control relay "B" is functioning properly. This means that the PTO switch, right steering switch and left steering switch are functioning properly. Check if fuel solenoid is binding or has a broken spring. See Owner's Manual for location of the manual fuel stop lever. If lever can be pushed forward against spring pressure, fuel solenoid is operating properly. If lever is already forward, is binding, or has no spring resistance, replace fuel solenoid. KUBOT DIESEL MODELS WITH D902 ENGINES 27

28 ENGINE STRTS, BUT DIES WHEN STEERING LEVERS RE BROUGHT IN OR PTO SWITCH IS ENGGED LL MODELS tes: If engine will crank and start, the PTO switch, right steering switch and left steering switch are functioning properly. The problem must be the parking brake or seat switch. Steering levers IN, seat switch manually activated to simulate operator ON seat, parking brake OFF. Test will be to the battery positive side. Does only one side of the seat switch show ground? (te: wires must be installed on switch and switch must be activated.) Replace seat switch. YELLOW Brake Switch Test Points If neither side of the seat switch shows ground, replace parking brake switch. GREEN NC NO Brake switch view Figure Rev

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30 Steering levers OUT, PTO switch 'OFF', parking brake 'OFF'. Voltage tests are performed with a voltmeter or test light to battery ground (negative post) unless otherwise noted. Key switch is in 'RUN' position for each test unless otherwise noted. ENGINE STRTS, BUT DIES WHEN KEY SWITCH IS RELESED LL KUBOT DIESEL MODELS EXCEPT THOSE WITH D902 ENGINES tes: 1. ll tests are made with wires in place on their respective switches. 2. Problem is in the 'HOLD' circuit of the fuel solenoid. 3. Relay is the relay with 1 yellow, 2 black and 2 red wires. from terminal '' of main fuse to ground? (Refer to figure 24) from terminal 'B' of main fuse to ground? from terminal '1' of fuel solenoid module to ground? (Refer to figure 23) To continues on next page Replace key switch. Replace main fuse. from terminal 'G' of ignition/solenoid fuse to ground? Replace ignition/solenoid fuse. Replace control relay. This is the relay with 1 yellow, 2 black and 2 red wires. Fuel Solenoid Module Test Points Fuse Block Test Points Fuse block styles will vary. Be sure you are checking designated fuse. G H IGNITION / SOLENOID FUSE MP. PTO FUSE - 10 MP. MIN FUSE - 15 MP. B CCESSORY FUSE - 10MP. I J MSTER FUSE - 30 MP. Figure 23 STRT FUSE - 30 MP. Figure Rev

31 ENGINE STRTS, BUT DIES WHEN KEY SWITCH IS RELESED (CONTINUED) LL KUBOT DIESEL MODELS EXCEPT THOSE WITH D902 ENGINES continued from previous page Does ground appear from terminal '2' of fuel solenoid module to battery positive side? Repair ground. from terminal '4' of fuel solenoid module to ground? Replace fuel solenoid MODULE. IMPORTNT: If fuel solenoid module must be replaced, check fuel solenoid ohms. defective fuel solenoid could burn out a new fuel solenoid module. Solenoid 'HOLD' to 'COMM' wires should test approximately 11 to 16 ohms resistance. from 'HOLD' wire of fuel solenoid to ground? Check fuel solenoid plug connection. Replace fuel solenoid. Solenoid 'HOLD' to 'COMM' wires should test approximately 11 to 16 ohms resistance. + - RED / WHITE KEY SWITCH RED / WHITE (In run position) BTTERY CBLE C RED RED MIN FUSE RELY YELLOW / BROWN TO SFETY SWITCHES SOLENOID FUSE RED 4 3 WHITE FUEL SOLENOID MODULE GREEN HOLD PULL COMM FUEL SOLENOID STRTER IN-LINE FUSEHOLDER Figure 25 Rev

32 Steering levers OUT, PTO switch 'OFF', parking brake 'OFF'. Voltage tests are performed with a voltmeter or test light to battery ground (negative post). Key switch is in 'RUN' position for each test unless otherwise noted. ENGINE STRTS, BUT DIES WHEN KEY SWITCH IS RELESED KUBOT DIESEL MODELS WITH D902 ENGINES tes: 1. ll tests are made with wires in place on their respective switches. 2. Problem is in the 'HOLD' circuit of the fuel solenoid. 3. Relay is the relay with 1 yellow, 2 black and 2 red wires. from terminal 'D' of fuel solenoid module to ground? (Refer to figure 26) from terminal 'E' of fuel solenoid module to ground? Call Grasshopper Service Department from terminal 'G' of ignition fuse to ground? Replace ignition fuse. Replace control relay. This is the relay with 1 yellow, 2 black and 2 red wires. from terminal '' of main fuse to ground? (Refer to figure 27) from terminal 'B' of main fuse to ground? Check for broken wire between fuse block and fuel solenoid module. Replace key switch. Replace main fuse. Fuel Solenoid Module Test Points Fuse Block Test Points Fuse block styles will vary. Be sure you are checking designated fuse. G H IGNITION FUSE MP. PTO FUSE - 10 MP. MIN FUSE - 15 MP. B CCESSORY FUSE - 10MP. B C D E MSTER FUSE - 30 MP. Figure 26 STRT FUSE - 30 MP. Figure I J

33 ENGINE STRTS, BUT DIES WHEN KEY SWITCH IS RELESED BRIGGS & KOHLER MODELS tes: 1. If engine cranks and starts but dies when key switch is released, then PTO switch, right and left steering switches, carburetor solenoid and stop relay are functioning properly. 2. Problem is a blown light/aux. fuse, a fuse block connection or a bad key switch. 3. ll tests are made with wires in place on their respective switches. Steering levers out, PTO switch 'OFF'. Voltage tests are performed with a voltmeter or test light to ground (negative post). Key switch is in 'RUN' position for each test. at top of light/aux fuse to ground? Problem is fuse on bottom of light/aux fuse clip or wire to to ground? carburetor solenoid. Does voltage appear from terminal 'L' of key switch to ground? Problem is light/aux fuse clip or wire from key switch to fuse. Replace fuse. Replace Key switch 33

34 ENGINE STRTS ND RUNS, BUT WILL NOT SHUT OFF KUBOT DIESEL MODELS WITH D902 ENGINES Turn key switch on, then off. Does voltage appear on terminal B of stop solenoid module to battery ground for approx. 10 seconds from time key was turned off? Key switch is in RUN position for each test, but engine is not running. Does coil resistance of stop solenoid measure approx. 1 Ohm to ground? Replace stop solenoid. TO continues on next page tes: 1. Check STOP SOLENOID fuse (15 amp). The engine will not shut off if this fuse is blown or if fuse block terminals are loose or corroded. 2. IMPORTNT:. For the tests on this page, unplug stop solenoid. B. Before performing tests, check ground source for fuel solenoid module. The starter plate on the right side of the engine has two ground bolts. The fuel solenoid module ground wire is green with a yellow tracer and is connected to the TOP bolt. Tighten this connection if it is loose. If connection is already tight, check for damaged wire at eyelet. 3. Check for DC voltage in all tests. 4. Steering levers out, PTO off for all tests. 5. Remember to reconnect stop solenoid when testing is completed. Check linkage to fuel shutoff for binding. Fuel Solenoid Module Test Points D E C B Fuse Block Test Points Fuse block styles will vary. Be sure you are checking designated fuse. IGNITION FUSE MP. PTO FUSE - 10 MP. MIN FUSE - 15 MP. G H B CCESSORY FUSE - 10MP. I J MSTER FUSE - 30 MP. Figure 28 STRT FUSE - 30 MP. Figure 29 34

35 ENGINE STRTS ND RUNS, BUT WILL NOT SHUT OFF continued from previous page (CONTINUED) KUBOT DIESEL MODELS WITH D902 ENGINES Does voltage appear from terminal D of stop solenoid module to ground? Does voltage appear from terminal E of stop solenoid module to ground? Replace fuel solenoid module Does voltage appear from terminal G of IGN/Relay fuse to ground? Does voltage appear from terminal H of IGN/Relay fuse to ground? Check for loose terminal in fuse block or broken wire. Replace relay Replace IGN/Relay fuse Does voltage appear from terminal of main fuse to ground? Does voltage appear from terminal B of main fuse to ground? Check for loose terminal in fuse block or broken wire. Replace key switch. Replace main fuse. BTTERY KEY SWITCH IN RUN POSITION RED/WHITE MIN FUSE RED/WHITE STOP SOLENOID MODULE STOP SOLENOID RED BTTERY CBLE RED D E C B RED RELY YELLOW TO SFETTY SWITCHES IGN/ RELY FUSE GREEN/YELLOW RED STOP SOLENOID FUSE WHITE/RED BLUE/WHITE Figure 30 35

36 TROUBLESHOOTING PTO CLUTCH Steering levers OUT, PTO switch ON. Voltage tests are performed with a voltmeter or test light to battery ground (negative post) unless otherwise noted. Key switch is in RUN position for each test, but engine is not running. LL MODELS EXCEPT KUBOT tes: WRNING! DO NOT HVE ENGINE RUNNING DURING NY PRT OF THIS TEST. 1. If the tractor is equipped with a PowerFold deck, be sure the safety switch on the bottom of the actuator switch mount is fully depressed when the mount is down on the actuator rod. If the plunger is not fully depressed when down, the clutch will not operate. Loosen the switch mount pivot bolt if needed to allow spring pressure to hold the mount down fi rmly on the rod. If voltage is present at terminal 85 on Relay E when the plunger is fully depressed, contact Grasshopper Service. (See Figure 31. This relay is located inside the console or on the left side of the frame near the brake switch.) 2. Test clutch by reading ohm's across clutch plug. Remove wire connector at clutch plug. See chart on page 38 for acceptable resistance readings. from terminal E of PTO fuse to ground? B 30 REGULTOR FUSE Problem is the key switch or wiring from key switch to PTO fuse. Does green wire of tractor harness plug show ground when tested to battery positive side? Repair clutch ground circuit. DC 7.5 STRT FUSE FE 10 from terminal F of PTO fuse to ground? PTO FUSE HG 7.5 LIGHT FUSE Replace PTO fuse. Test PTO clutch and terminals (see note above). from brown wire at PTO clutch plug to ground? Replace PTO switch. Choose the style that matches the style on the unit you are troubleshooting. Fuse block styles will vary. Be sure you are checking designated fuse. Figure 31 RELY TERMINL REFERENCE Figure Series 700 Series 30 TO UNIVERSL HRNESS GREEN BROWN BROWN E BROWN Fuse Block Test Points LIGHT/UX FUSE 7.5 MP. PTO FUSE 10 MP. STRT FUSE 30 MP BROWN TO UNIVERSL HRNESS MSTER FUSE 30 MP. REGULTOR FUSE 30 MP. CCESSORY FUSE UNIVERSL HRNESS FUSE 10 MP CCESSORY FUSE KEY SWITCH (In run position) PTO SWITCH (PTO on) CLUTCH +- RED S L BROWN BROWN M PTO B FUSE G GREEN Figure Rev

37 TROUBLESHOOTING PTO CLUTCH Steering levers OUT, PTO switch 'ON'. Voltage tests are performed with a voltmeter or test light to battery ground (negative post) unless otherwise noted. Key switch is in 'RUN' position for each test, but engine is not running. from bottom terminal of PTO fuse to ground? Replace PTO fuse. LL KUBOT MODELS tes: WRNING! DO NOT HVE ENGINE RUNNING DURING NY PRT OF THIS TEST. 1. If the temperature light is on, turn to page 39 for troubleshooting steps. 2. If the tractor is equipped with a PowerFold deck, be sure the safety switch on the bottom of the actuator switch mount is fully depressed when the mount is down on the actuator rod. If the plunger is not fully depressed when down, the clutch will not operate. Loosen the switch mount pivot bolt if needed to allow spring pressure to hold the mount down fi rmly on the rod. If voltage is present at terminal 85 on Relay E when the plunger is fully depressed, contact Grasshopper Service. (See Figure 35. This relay panel is located inside the console.) 3. If engine starts and runs, relay '' is working properly. 4. Test clutch by reading ohm's across clutch plug. Remove wire connector at clutch plug. See chart on page 38 for acceptable resistance readings. 5. Voltage tests are performed with the seat switch wires removed and a jumper installed across the two wires. Warning! Jumper must be removed and wires reinstalled on seat switch after test is complete and before machine is returned to operation. from brown wire at PTO clutch plug to ground? Replace PTO switch. Does green wire of tractor harness plug show ground when tested to battery positive? Repair clutch ground circuit. Test PTO clutch and terminals (see note above). Figure 35 Fuse Block Test Points Fuse block styles will vary. Be sure you are checking designated fuse. STRT FUSE 30 MP. Rev IGNITION FUSE 7.5 MP. PTO FUSE 10 MP. MIN FUSE 15 MP. CCESSORY FUSE 10 MP. MSTER FUSE 30 MP. Figure 34 RELY TERMINL REFERENCE RED KEY SWITCH (in run position) RER OF TRCTOR C G RED / WHITE I GREEN MIN FUSE RED / WHITE 37 RELY YELLOW / BROWN B GREEN RED TO SFETY SWITCHES TEMP. PURPLE PURPLE C PURPLE PTO FUSE PURPLE GREEN D BROWN PNEL PD G PTO SWITCH (PTO on) BROWN TO UNIVERSL HRNESS CLUTCH GREEN BROWN BROWN E BROWN PNEL PD M BROWN BROWN TO UNIVERSL HRNESS FRONT OF TRCTOR Figure 36 GREEN CLUTCH

38 CCEPTBLE CLUTCH RESISTNCE RNGE IN OHMS FOR TRCTORS WITH SERIL NUMBER & BOVE FRONT MOUNTS MID MOUNTS 100 Series 225V & 226V Series except 225V & 226V 616T 620T & 623T 700 Series with Kohler engines & Briggs Big Block engines ll 700 & 900 Series Kubota Models 1" Clutches 1.125" Clutches 1" Clutch with 1.125" Clutch with Center Stop* Center Stop & 1" Spot & 1.125" Spot Brake Clutch** Brake Clutch** * 'Center Stop' refers to the stainless steel piece located between the hold magnets. To check if the clutch has this stop, look on the front side of the anti-rotation flange. ** The Spot Brake Clutch can be identified by a one piece plate bolted on the front side of the anti-rotation flange. 38

39 HIGH TEMPERTURE CLUTCH CUTOUT WIRING When the engine overheats, the temperature gauge shows hot. This triggers a ground through the purple wire of the temperature gauge. This ground activates the temperature light ND causes the clutch to disengage. When ground via the purple wire activates relay D, voltage to the clutch is terminated at this relay. Relay C is also activated, and hard ground is diverted to its center terminal. This relay will therefore remain grounded and prevent the purple wiring from losing ground. The circuit will remain in this state until the key switch is turned off again. The ground at the purple wire will then be eliminated, but only if the engine has cooled to a safe operating temperature. The clutch will then operate again. If the clutch does not work after the system has been reset by turning the key switch off, contact Grasshopper Service. VERIFICTION OF WHETHER THIS CIRCUIT IS SHUTTING DOWN THE CLUTCH FUNCTION Using a DC voltmeter, check from battery negative. Is voltage present on brown wire at terminal 85 on Relay E? Using a DC voltmeter, check from battery positive. Is ground present on double purple wire at terminal 86 on Relay D? The high temperature clutch cutout wiring is not shutting down the clutch function. See NOTE 2 on page 37 for troubleshooting guidelines. Engine overheating is the cause. Ground at terminal 86 will disappear when the system resets. If confirmed that the engine has cooled down to a safe operating temperatue but the system does not reset, contact Grasshopper Service. The high temperature clutch cutout wiring is not shutting down the clutch function. See page 37 for troubleshooting guideline for possible causes of clutch malfunction. RELY TERMINL REFERENCE CLUTCH BROWN G I 30 TEMP. PURPLE PURPLE PURPLE BROWN GREEN TO UNIVERSL HRNESS BROWN BROWN TO UNIVERSL HRNESS B C D E RER OF TRCTOR GREEN GREEN BROWN FRONT OF TRCTOR PURPLE GREEN PNEL PD G PNEL PD M Rev

40 TROUBLESHOOTING ELECTRIC LIFT (STRP STYLE) PGE 1 OF 5 RED/WHITE B C D E F YELLOW Figure 37 GREEN/YELLOW ELECTRIC LIFT DOES NOT OPERTE tes: 1. For testing refer to 6-way Weather-pack located next to the brake lever. 2. Connector view is from back (wire side) (see Figure 37). 3. Toggle switch is not activated. RED/WHITE RELY RED/WHITE RELY B GREEN/YELLOW GREEN/YELLOW GREEN/YELLOW GREEN/YELLOW GREEN/YELLOW YELLOW/BROWN /WHITE B YELLOW BLUE PURPLE Figure 38 Figure 39 NOTE: ll tests are performed with plug connected. To access Weather-Pack terminals, use a small screwdriver to release latches on either side of cover. Flip up cover and slide green cable seals up the wires to expose terminals. Do not penetrate wire covering to test. This can lead to wiring component failure. on terminal B of 6-way connector to ground? (red/white wire) NOTE: NO Check 40 MP inline fuse (Universal Harness) YES Does terminal F on 6-way connector show ground to battery positive side? (green/yellow wire) NO NO NO NO Faulty ground in Universal Wiring Harness YES Key switch is in RUN position for remainder of test. Dose voltage appear on terminal D of 6-way connector to ground? (black wire) NO Check accy fuse in fluseblock Disconnect two wires from winch motor. If fuse repeatedly blows, check for pinched wires. Be sure to reconnect wires to winch. If fuse does not blow with wires disconnected, winch motor may be defective. Does voltage appear on red/white wire of relay and B to ground? Check wiring between 6-way and relay Go to page 41 Does green/yellow wire of relay and B show ground to battery positive side? YES YES Check ground in Universal Wiring Harness ctivate electric lift switch to down position. Does blue wire of relay show ground to battery positive side? Replace relay YES NO YES ctivate electric lift switch to up position. Does purple wire of relay B show ground to battery positive side? Replace relay B YES 40

41 TROUBLESHOOTING ELECTRIC LIFT (STRP STYLE) PGE 2 OF 5 What is the position of the winch Is winch in the up position and will not lower? YES Is winch positioned between upper and lower limit switches? But won t raise or lower? YES Is winch in the down position and will not raise? YES Go to page 42 Redo test on previous page Go to page 43 41

42 TROUBLESHOOTING ELECTRIC LIFT (STRP STYLE) PGE 3 OF 5 RED/WHITE GREEN/YELLOW /WHITE B RELY B GREEN/YELLOW YELLOW PURPLE Figure Figure 41 ctivate electric lift switch to down position Does black/white wire of Relay B show voltage to ground? YES Does yellow wire of Relay B show ground to battery positive side? YES Does purple wire of winch motor show voltage to ground? YES Faulty winch motor NO NO Replace lower limit switch. Lower limit switch is nearest winch (see Figure 41) NO Replace Relay B Replace toggle switch 42

43 TROUBLESHOOTING ELECTRIC LIFT (STRP STYLE) PGE 4 OF 5 RED/WHITE RELY GREEN/YELLOW GREEN/YELLOW GREEN/YELLOW YELLOW/BROWN BLUE Figure Figure 43 ctivate electric lift switch to up position. Does voltage appear on yellow/brown wire of switch to ground? NO YES Does yellow/brown wire of Relay show voltage to ground? NO YES Does blue wire of winch motor show voltage to ground? NO YES Faulty winch motor Replace toggle switch Replace Relay on both yellow/brown wires of upper limit switch? Upper limit switch is farthest from winch motor (see Figure 43). Be sure wire terminals are tight and installed correctly. NO Replace upper limit switch 43

44 TROUBLESHOOTING ELECTRIC LIFT (STRP STYLE) PGE 5 OF 5 WIRING DIGRM BLUE TOWRD TRCTOR PURPLE TOWRD ERVTOR BLUE UPPER LIMIT SWITCH LOWER LIMIT SWITCH GREEN/YELLOW YELLOW/BROWN 7 MUST BE CONNECTED FOR ER-VTOR LIFT MUST BE DISCONNECTED FOR SNOWTHROWER LIFT GREEN/YELLOW WHEN REMOVING ER-VTOR FROM TRCTOR DISCONNECT WIRING T THIS POINT F E D C B B C D E F 6-WY MLE PLUG FROM UNIVERSL TRCTOR HRNESS 6-WY FEMLE PLUG YELLOW YELLOW 3 RELY MOUNT THIS IS DOUBLE WIRE ON SWITCH 5 5 RED/WHITE 4 B SWITCH BOX 6 6 /WHITE YELLOW/BROWN Item Order Description Wiring ssembly (includes items 1 & 3-7) Connector - 6 way Switch Diode Switch - Rocker Switch Item Order Description Relay Connector - 5 way Female Terminal Eyelet Insulator Lift Drive ssembly Connector - Pin Housing Connector - Housing 44

45 HYDRULIC DOZER ELECTRICL TROUBLESHOOTING F E D C B Relay 1 Relay 2 WHITE RED/WHITE GREEN/YELLOW GREEN/YELLOW GREEN RED/WHITE RED/WHITE GREEN/YELLOW B C B C D D WHITE /WHITE /WHITE E E F F GREEN/YELLOW 7 8 WHITE YELLOW/BROWN 2 1 YELLOW/BROWN GREEN/YELLOW YELLOW/BROWN 4 6 BLUE/WHITE BLUE D 5 B C The hydraulic dozer blade wiring harness contains six diodes for controlling the direction of current fl ow. When a diode allows voltage to reach the solenoids, oil pressure controls the up and down functions. When a diode stops voltage from reaching the solenoids, oil pressure controls the left and right functions. te: 1. Voltage tests are performed with a DC voltmeter. ll voltage tests are from the battery negative terminal. 2. If a diode must be replaced, locate the ring on the diode and orient the same way as the existing diode. Problem: Dozer blade goes LEFT when switch activated to go DOWN. Is voltage present at location 1? Is voltage present at location 2? Contact Grasshopper Service Department. Check for poor connection at location 3. Replace diode. Problem: Dozer blade goes RIGHT when switch activated to go UP. Is voltage present at location 4? Is voltage present at location 5? Contact Grasshopper Service Department. Check for poor connection at location 6. Replace diode. Problem: Direction of movement is erratic when switch activated to go DOWN or LEFT. May go down of left randomly. Diode between '1' and '2' OR at '7" is shorted. Solution: *Replace shorted diode. Problem: Direction of movement is erratic when switch activated to go UP or RIGHT. May go up or right randomly. Diode between '4' and '5' OR at '8' is shorted. Solution: *Replace shorted diode. *Checking for shorted diode: Place meter on ohms and check for resistance both ways. good diode will show continuity in one direction only. shorted diode will show continuity in both directions. 45