SECTION ELECTRICAL SYSTEM

Transcription

1 6-0.0/ BATTERIES 8D 004AL SECTION ELECTRICAL CIRCUITS CAUTION: Nova LFS buses are equipped with a negativeground electrical circuit. DO NOT inverse the polarities while using an auxiliary battery as a backup power source; it could seriously damage the alternator, the voltage regulator, the batteries and the battery cables. DO NOT use the alternator s DC (direct current) terminal. A connector, used for the connection of the emergency auxiliary batteries, is available in the engine compartment, at the rear of the vehicle. COACH WIRING DIAGRAM The electrical circuit subdivides into several separate circuits, where each system is classified according to its function. A COACH WIRING DIAGRAM is provided with each customer order. All cables routing from the electrical equipment box to the engine compartment are covered with black heat-resistant tape. To facilitate the connection, a label near each cable end bears the number or abbreviation of the terminal to which it is connected. CIRCUIT TESTING The COACH WIRING DIAGRAM should be carefully studied in order to identify current source and flow through each electrical circuit. Once a circuit is thoroughly understood, a point-to-point check can be made using the applicable wiring diagram to determine where a failure occurred. All electrical connections should be kept clean and properly tightened. Loose or corroded connections will cause battery discharge, difficult starting and faulty operation of other circuits. Examine all cable connections regularly. Make sure all nuts on all electrical plugs and connectors are securely tight. ELECTRICAL CONNECTIONS The electric circuit connections are obtained by the means of multiport plugs and terminal boards. The letters on the plugs and outlets correspond to the letters shown in the electric diagrams. The plugs are provided with locating pins, which ensure a good connection between a plug and a jack. ENGINE COMPARTMENT DOOR CONNECTION The engine wiring harness of the compartment door, which supports the circuits to the stoplights, turn signal lights, taillights and license plate lamp, is connected to the electrical multiplex modules through an electrical connection located in the engine compartment. OPERATOR S CONTROL PANEL CONNECTIONS For more information on components and electrical connections in the operator s control panel, see the COACH WIRING DIAGRAM. BATTERY CONNECTIONS Battery cable connections are found at various locations on the vehicle. The cables follow the wall behind the operator and wind their way into the ceiling on the left side towards the engine compartment. Grounding cables are positioned halfway along the vehicle, between the roof unit and the structure of the bus. Other connections are located in the battery compartment and near the power steering gearbox. The other connection cables lie in the engine compartment. The battery cables, which feed current to various vehicle parts for electrical system and component operation, are linked to these connections. All connections should be kept clean and securely tight. If they are corroded, disconnect the cables and thoroughly clean the cable ends and connecting studs. Connect the cables to the studs and firmly tighten the stud nuts.

2 $ 004AL / PANELS IN THE OPERATOR S AREA See the Nova Bus OPERATOR S MANUAL for more information on the instrument panel s various indicators, warning lights and audible signals. CAUTION: Before removing, dismantling or maintaining any electrical component, the electrician should take the necessary precautions to avoid any risk of personal injury or damage to the equipment. See the provided COACH WIRING DIAGRAM for further details on electrical circuit power cut-off points.. TELL-TALE (INDICATORS AND WARNING) LIGHTS. PRESSURE GAUGE. SPEEDOMETER Figure - Typical Indicator and Warning Light Panel INDICATOR AND WARNING LIGHT PANEL See Figure. The indicator and warning light panel is mounted directly in front of the operator. The indicator and warning light housings are secured into the dashboard by screws at both strip ends. They are arranged in two horizontal rows in the upper center of the instrument panel. Lamps within the dials and indicator housings illuminate the various indicator and warning light faceplates as well as the speedometer and pressure gauge dials. The symbols on the warning lights are visible only when the lamps light up. OVERHEAD CONTROL PANEL See Figure. The OPERATOR S MANUAL explains the significance of the symbols on the overhead panel and how they work. For more information on the components and connections of the overhead control panel, see the COACH WIRING DIAGRAM. SWITCHES See the OPERATOR S MANUAL for more information on the switches. Figure - Overhead Control Panel.SIDE CONSOLE.PNEUMATIC CONTROLS.MASTER CONTROL SWITCH 0078 OPERATOR S SIDE CONTROL PANEL See Figure. The switches used by the operator for normal vehicle operation are located on the side control panel on the left-hand side of the operator. Figure - Typical Side Control Panel

3 6-0.0/ BATTERIES 8D 004AL MASTER CONTROL SWITCH The MASTER CONTROL SWITCH panel bears symbols that allow quick identification of the required function. The chosen circuits activate when the switch is turned so that the arrow on the knob aligns with the symbol on the panel. In some cases, the MASTER CONTROL SWITCH only provides power to a circuit controlled by another switch or relay. The OPERATOR S MANUAL specifies the switch positions and the circuits each one controls. OPERATOR'S MAIN PANEL The operator s main panel is located above the operator s compartment and accessed through two separate panels. A special key is required to access the components fitted on these two panels, which mainly include circuit breakers, relays, diode arrays, and resistors. See the COACH WIRING DIAGRAM for information on electrical components and connections in the operator s main panel. CAUTION: Push the release button to manually release a circuit breaker before working on the auxiliary terminals and thus prevent any possible short circuit in the connecting flange terminals. OTHER ELECTRICAL COMPONENTS AND PANELS Numbers inscribed beside the components description correspond to numbers in Figure 4. Electrical components closely related to other systems or units are covered in other sections within this manual. CAUTION: Before removing, dismantling or maintaining any electrical component, the electrician should take the necessary precautions to avoid any risk of personal injury or damage to the equipment. See the provided COACH WIRING DIAGRAM for further details on electrical circuit power cut-off points. SLIDING BATTERY TRAY () Located at the left front of the vehicle, underneath the floor, it includes two batteries, a 4/-volt converter and a 4-volt switch. See section 6-0: BATTERIES in this manual for additional information on batteries. See section 6-0: EQUALIZER in this manual for additional information on this component. CIRCUIT BREAKER PANEL AND MAIN CIRCUIT BREAKER () These components are located to the left of the operator, behind the floor-level access panel. See the COACH WIRING DIAGRAM for further details on circuit breakers and their electrical connections. The 4-volt main circuit breaker cut-off lever and the -volt switch are accessible from the battery compartment. ELECTRIC HORNS () The two horns are located at the front of the vehicle, on the left-hand side. Each has its own pitch. Both are carefully adjusted and examined during manufacturing and should work indefinitely without need for maintenance or inspection. They should never be adjusted or repaired. If one no longer operates, it should be replaced. However, the fault could lie in the external circuit. A quick check can be carried out with a jumper wire. See the COACH WIRING DIAGRAM to determine the horn circuit s check points. OPERATOR S SAFETY COMPARTMENT (4) Located above the operator s window, this compartment contains a radio module with turnkey switch, a buzzer that sounds when the emergency unlocking control is enabled, and an emergency unlocking system reset switch. These components are accessed by giving the compartment door handles a quarter turn and lifting the swingout door. See the COACH WIRING DIAGRAM for additional information on these components electrical circuits.

4 004AL 4 / OUTPUT FUNCTION RETARDER AND DIFFERENTIAL OUTPUT FUNCTION REVERSE WARNING OUTPUT FUNCTION NEUTRAL START IGNITION FUSE ECU POWER FUSE 4 5 ONLY INSTALLED WITH ALLISON TRANSMISSIONS 6 OPERATOR S SAFETY COMPARTMENT TRANSMISSION CONTROL MODULE (VIM) - (OPTIONAL) TRANSMISSION ELECTRONIC CONTROL MODULE (ECU) (OPTIONAL LOCATIONS) FOR ECU - ITEM # ELECTRIC HORNS 7 STARTER CIRCUIT BREAKER PANEL AND MAIN CIRCUIT BREAKER SLIDING BATTERY TRAY TRANSMISSION CONTROL MODULE (VIM) - (OPTIONAL) (5) This unit is only installed with the Allison transmission. The electronic control module (VIM) supplies the necessary relays and all the connection points to interface with the electrical systems of the vehicle. The electronic control module contains two fuses which offer to the ECU a protection against faults and overvoltage of the vehicle. The relays perform signal transfers from the ECU, allowing to control certain functions of the bus. TRANSMISSION ELECTRONIC CONTROL MODULE (ECU) (6) Located in the rear, above the last left-hand side passenger seat, the ECU controls the transmission. It receives information from the throttle position sensor, the vehicle speed sensor, the pressure switches and the transmission push-button selector. The ECU processes these data and controls the transmission via solenoids located on the transmission control module. Figure 4 - Electrical Component Locations In addition, the ECU monitors the system for conditions that could damage the transmission or cause poor performance during normal vehicle operation. When such conditions are detected, the ECU is programmed to respond automatically, to ensure safe operation of the transmission, and more generally, of the vehicle. See the COACH WIRING DIAGRAM for information on components in the ECU circuits. See the transmission manufacturer s repair manual for additional details on the ECU. STARTER (7) Located in the engine compartment, the starter is easily accessed by opening the left rear side panel. For additional details on the starter, see section 09-00: STARTING SYSTEM in this manual.

5 6-0.0/ 5 BATTERIES 8D 004AL S In some cases, relays are used to automatically open or close a circuit according to operating conditions. In other cases, they provide a direct link between the battery and an electrical device, with only very low current required to switch on the operating coil through the control switch. They also eliminate the need for long, heavy wires and cables. Several relays of the same type are used on each vehicle; however, they are used in different circuits for different purposes. SPEEDOMETER AND ODOMETER The electronic speedometer interprets the positive square waves received from the VIM and converts the data into physical motion of the speedometer needle to show the ground speed of the vehicle. The odometer indicates the distance covered by the vehicle. ODOMETER CALIBRATION Calibration of the odometer implies that it is adjusted according to the hubodometer. Proper odometer calibration is essential for an accurate reading of distance covered. VERIFICATION. Note the mileage currently inscribed on the dashboard odometer.. Note the mileage inscribed on the hubodometer, located on the right rear wheel of the vehicle.. Calculate the difference between the two odometers. 4. Make the vehicle cover a minimal distance of 5 miles (5 km) and repeat the preceding steps. 5. There should not be a difference of more than 5 % between both results. See Table : 6. If the odometer is not calibrated properly, execute the following adjustment procedure. ADJUSTMENT See Figure 5.. Adjust the dip switches located behind the speedometer with odometer according to the sequence indicated on the corresponding wiring diagram.. Set a multimeter to the voltage indicated on the label of the speedometer.. Adjust the multimeter at the frequency indicated on the wiring diagram and connect it to the indicator connecting plugs. The sequence of the dip switches is based on a PUSH / CLOSE type request. 4. Bring the speedometer to 80 mph (0 km/h) using the adjustment screw. Thirty seconds at 80 mph (0 km/k) equals an additional 0.6 mile ( km) on the odometer. TROUBLESHOOTING SPEEDOMETER HEAD a) If the speedometer does not indicate zero speed when the ignition key is in the ON position and the engine is running, there could be interference from the alternator. In this case, re-route the signal wire to eliminate any interference. b) If the instruments are irregular when the horns are actuated, connect a 6-gauge wire from the instrument s negative (-) terminals to one of the U-shaped connecting studs. Make sure the negative terminals are properly grounded. DASHBOARD ODOMETER FIRST VERIFICATION 0 mi 45 mi HUBODOMETER 0 mi 5 mi DIFFERENCE 0 mi 0 mi SECOND VERIFICATION RESULT: The odometer on the dashboard is well calibrated OPEN CLOSED OPEN DIP SWITCHES ADJUSTMENT SCREW PR LAMP M CONNECTING PLUGS - Table - Odometer Verification Figure 5 - Odometer Adjustment

6 004AL 6 / ELECTRICAL NOISES Electric noises are caused by the electromagnetic waves usually generated by conductors carrying strong currents, high commutation circuits and apparatus, such as the engine, the alternator and the transformer. In certain very rare cases, the instruments can react by an excessive deviation of the needles. In order to overcome the effects of electromagnetic induction:. the power cables should not be installed in parallel with the test cables in the same wiring system, OR. the power cables and the test cables must be passed in a perpendicular manner, OR. the test cables must have an armed sheath, and only one side of the sheath must firmly be grounded. Make sure the other side of the sheath is isolated. SPEEDOMETER REPLACEMENT CAUTION: Do not disconnect the speedometer s wiring when it is live. Internal damages to the ECU could occur if wires are crossed or grounded during removal or installation. LIGHTING SYSTEM GENERAL The COACH WIRING DIAGRAM shows the interior and exterior lighting circuits and their control switches, relays and circuit breakers, the indicator and warning lights, the stoplights, the turn signal, and other types of lighting. See the LADDER DIAGRAM for multiplex controls. WARNING: All headlights, exterior lights, and indicator and warning lights should be checked daily and all necessary changes made on the spot. See the NovaBus PARTS MANUAL to find out about the appropriate replacement bulbs. HEADLIGHTS Headlights are of the two-wire type, since they comprise a high and a low beam. They are identified as Type D, and this code is molded into the top of the lens. The unit cannot be repaired and should be replaced when a faulty operation is detected. Before replacing the speedometer s head, the following verifications must be carried out: a) Check the connections and the cables to make sure the connections on the terminals are correct. b) Check to make sure no parts of uninsulated wire are in contact. c) Follow the signal cable to check if it is connected correctly to the source of the signal. d) Verify that the + and - connections are connected firmly. e) Check the fuses. f) Check to detect shorted-circuit cables. 4. HEADLIGHT MOULDING. HOLDING RING. HEADLIGHT 4. ADJUSTING SCREW Figure 6 - Typical Headlight Figure 7 - Front Headlight Mounting

7 6-0.0/ 7 BATTERIES 8D 004AL SIDE MARKER LIGHTS. REFLECTOR. TURN SIGNAL AND SIDE MARKER LIGHTS 4. KNEELING LAMP 5. OVERHEAD DOOR LIGHTING Figure 8 - Side Lights and Reflectors 5. HEADLIGHTS. LEFT TURN SIGNAL LIGHT. RIGHT TURN SIGNAL LIGHT 4. CLEARANCE LIGHTS 5. MARKER LIGHTS. REAR CENTER BRAKE LIGHT. REFLECTORS. RIGHT BACKUP LIGHT 4. RIGHT TAIL AND STOP LIGHT 5. RIGHT TURN SIGNAL LIGHT 6. LEFT BACKUP LIGHT 7. LEFT TAIL AND STOP LIGHT 8. EFT TURN SIGNAL LIGHT 9. REAR CLEARANCE LIGHTS 0. MARKER LIGHTS. LICENSE PLATE LIGHT Figure 9 - Front View of The Bus Figure 0 - Rear View of The Bus

8 004AL 8 / Circuit breakers protect all lighting circuits. For the location of all circuit breakers, see the CIRCUIT BREAKER PANEL AND MAIN CIRCUIT PANEL heading in this section. Also, see the COACH WIRING DIAGRAM for further details on circuit breaker capacities. Light unit lenses contain three projecting locating points, which are optically frosted, in order to provide flat surfaces at a right angle to the beams. This design allows the adjustment of headlight aim during full daylight, without the need for a headlight alignment screen or a large work area. Adjustment is carried out using an appropriate headlight aimer. Always follow instructions provided by the manufacturer for using this device. REMOVAL OF THE LIGHT UNIT. Remove the screws securing the headlight molding to the front trim panel and remove the frame.. Place the holding ring onto the lens and secure it to the retaining ring.. Remove the light unit and disconnect the wiring connecting the plug behind this unit. INSTALLATION OF THE LIGHT UNIT A light unit bearing code number D in the upper part of the lens has to be used.. Connect the wiring connecting plug behind the light unit. Position the unit in the retaining ring so that the fixing brackets behind the unit slide into the retaining ring holes. The code number molded into the lens should face upward.. Place the holding ring onto the lens and secure it with the retaining ring. Checking and aiming the beam is necessary, even if the headlight was correctly aimed before replacement of the light unit, and even if the adjusting screws were not removed.. After installation and aiming, install the headlight molding. HIGH/LOW-BEAM SWITCH The lever-control switch on the steering column allows selecting the high or low headlight beam. See the OPERATOR'S MANUAL for this switch s operating conditions. The high/low-beam switch requires no maintenance, except keeping the cable connections securely tightened. If the switch fails, it must be replaced. See section 07: STEERING COLUMN in this manual to find out the replacement method. STOPLIGHTS The stoplights include the left and right rear combined tail and stoplights, a rear stoplight, pneumatic switches mounted at the front of the vehicle (see section 08: PNEUMATIC SYSTEM module for details on switch positions), a lamp monitor mounted on the operator s connection panel, and a stoplight warning light on the instrument panel. See the COACH WIRING DIAGRAM for further details concerning operation of the signal lights. STOPLIGHT PRESSURE SWITCH See Figure. The electropneumatic stoplight switches work jointly with the brake valve and stoplights to complete the electrical circuit when the operator applies the brakes. When the operator applies the brakes, the brake valve's air pressure penetrates the cavity under the diaphragm. At about 5 psi (4.4 kpa), the air pressure under the diaphragm exceeds spring force and moves the piston or plunger until the contact points close; this completes the circuit and turns on the stoplights. Inspect the electrical connections every month or every0,000 miles (6,000 km). Removal and Installation. Disconnect the electrical connections to the stoplight switch.. Expel the air from the system.. Disconnect the switch's air line. 4. Remove the switch. 5. Follow the preceding steps in reverse order to install the new switch. Figure - Typical Pressure Switch

9 6-0.0/ 9 BATTERIES 8D 004AL Testing. Operation Test a. Apply the brakes and confirm that upon the first downward motion of the brake pedal, the stoplight indicator lamp immediately turns on. b. Release the brake pedal and confirm that the stoplight indicator lamp turns on.. Sealing Tightness Test When the brakes are applied, the stoplight switch should not exhibit any leaks. PARKING BRAKE STOPLIGHT PRESSURE SWITCH The parking brake stoplight pressure switch is adjusted to a pressure of 80 psi (550 kpa). When air pressure at the feed port, and under the diaphragm, exceeds 80 psi (550kPa), the electrical contacts stay open, because the force exerted by the air pressure under the diaphragm exceeds that exerted by the spring above the diaphragm. When the air pressure under the diaphragm is less than 80 psi (550 kpa), the force of the spring is greater than the pressure of the air. This moves the diaphragm and piston and allows the electrical contacts to close. This completes the circuit to the parking brake stoplight relay. Every month, or every 0,000 miles (6,000 km), inspect the electrical connections. Every 00,000 miles (60,000 km), dismantle, clean and closely examine all parts. Replace all worn or deteriorated parts. Normal Operating Test. Operating Test To verify switch operation, set the MASTER CONTROL SWITCH to NORMAL DRIVING MODE, reduce air pressure and check whether the stoplight indicator lamp turns ON when pressure drops below 80 psi (550 kpa). The contacts will close when the indicator lamp turns ON.. Sealing Tightness Test When there is air pressure at the feed port, coat the switch with a soapy solution and check for leaks. NO leaks are permissable. Removal and Installation.. Set the MASTER CONTROL SWITCH to OFF-NORMAL DRIVING MODE.. Expel air from the system.. Remove the parking brake control tower. See section 08: BRAKING SYSTEM, for additional information. 4. Disconnect the electrical connections. 5. Disconnect the air line and remove the retaining bolts. 6. Replace the switch. 7. Follow the preceding steps in the reverse order to install the new switch. 8. Carry out the Operation Tests. TAILLIGHTS The taillights are combined with the stoplights. The stoplight circuit is powered when the master control switch is in NORMAL DRIVING MODE or NORMAL NIGHT DRIVING MODE position. LICENSE PLATE LIGHTING A license plate light is mounted above the top middle of the license plate, on the lower left-hand corner of the engine compartment door. The taillight circuit controls this light. To replace the bulb, take off the rectangular glass pane held in place by two bolts. Replace the defective bulb, and then put the glass pane back into place. Tighten the two bolts without overtightening. TURN SIGNALS The turn signals include two lamps located on the engine compartment door at the rear of the vehicle, two lamps at the front of the bus, and side lamps. Foot switches, located on the slanted floor panel to the left of the steering column, control the turn signals on the bus. The COACH WIRING DIAGRAM shows the relevant electrical circuits and connections. See the OPERATOR'S MANUAL for information on turn signal operation. HAZARD FLASHERS The hazard flashers include two rear, two front, and four side turn signal lights (two on each side, located near the wheelhouses). They are actuated by the emergency flasher switch on the dashboard. The COACH WIRING DIAGRAM shows the relevant electrical circuits and connections.

10 004AL 0 / SWITCH REPLACEMENT The toggle hazard flasher switch is held to the dashboard by a hexagonal nut. To remove the switch, remove the nut and the identification plate, and pull the switch out from under the dash panel. Make sure the wires are clearly identified before removing them from the switch, so that they are in correct position for installation. BACKUP LIGHTS The backup light switch, mounted on the gearbox, is actuated when the master control switch is in the NORMAL DRIVING MODE or LIGHTS position and the gearshift lever is in reverse. CLEARANCE AND MARKER LIGHTS Clearance and marker lights are mounted all around the vehicle. These light circuits are powered when the master control switch is in NORMAL NIGHT DRIVING MODE or the ACCESSORY position. INTERIOR LIGHTING EQUIPMENT FRONT AND REAR DOOR LIGHTING The rear doors exterior lighting works when the master control switch is in NORMAL NIGHT DRIVING MODE or the ACCESSORY position. The entrance door lighting, positioned above the floor, is controlled by a door switch that closes when the entrance door opens. The switch s circuit is powered when the master control switch is in NORMAL NIGHT DRIVING MODE or the ACCESSORY position. The bulbs are accessible once the lens is removed. The lens is secured to the casing with two screws. To replace the lamp, remove the grommet, remove and unplug the lamp and re-install a new kit. ENGINE COMPARTMENT LIGHTING A switch on the engine compartment control box controls engine compartment lighting. The bulbs are exposed and easily accessible. See the NovaBus PARTS MANUAL to determine replacement bulb part numbers. BULB REPLACEMENT In locations where bulbs are used, to remove the bulb, remove the screws holding the lens to the light unit body. Remove the lens, then unscrew and remove the bulb. Insert the new bulb and turn to secure into the socket. Reposition the lens and firmly tighten the lens retaining screws. Where replaceable LED type lights are used, merely replace the LED unit.