1996 Ford Taurus 3.0L Eng LX AIR CONDITIONING BLOWER CONTROL MODULE/BLOWER RESISTOR TEST G - BLOWER MOTOR OPERATES AT HIGH SPEED AT ALL SPEED SETTINGS 1. Check Blower Operation Disconnect RCC module harness connector. Ground Orange/Black wire. Turn ignition on. If blower operates, go to next step. If blower motor does not operate, replace RCC module. Retest system. 2. Check Blower Motor Speed Controller Turn ignition off. Reconnect RCC module harness connector. Remove Orange/Black wire from blower motor speed controller harness connector. Reconnect harness connector to speed controller. Using a jumper wire, connect Black wire and Orange/Black wire connector terminals at blower motor speed controller harness connector. Turn ignition on. If blower operates, replace blower motor speed controller. If blower motor does not operate, repair open Orange/Black wire. BLOWER DOES NOT OPERATE PROPERLY 1. Check Blower Motor Operation Ensure engine is off and ignition is on. Set A/C-heater selector switch to FLOOR position. Set blower motor switch to first position from HI. If blower operates, go to next step. If blower does not operate, go to step 4). 2. Check Blower Switch Positions Slowly move blower motor switch from LO position to HI position, stopping briefly at each position. If blower motor operates at any position except HI, go to step 4). If blower motor does not operate in any position except HI, go to next step. 3. Check Ground Circuit Check Black wire for open circuit between blower motor resistor and ground. If open circuit is found, repair wire as necessary. If wire is okay, replace blower motor resistor and retest system. 4. Check Circuit Check Orange/Black wire for open circuit between blower motor and blower motor resistor. If open circuit is found, repair Orange/Black wire as necessary. If wire is okay, replace blower motor resistor and retest system. 5. Check Blower Motor Switch Turn ignition on. Set blower motor switch in each position several times. If blower operates properly, no problem exists at this time. If blower does not operate properly, go to next step. 6. Check Blower Motor Switch Continuity Check continuity of blower motor switch in indicated positions. See BLOWER MOTOR SWITCH CONTINUITY TEST table. See Fig 1. If continuity is not as specified, replace blower motor switch. If continuity is as specified, repair open Black wire between blower motor switch and ground. BLOWER MOTOR SWITCH CONTINUITY TEST Switch Position Continuity Between Terminal No. http://www2.prodemand.com/print/index?content=tabs&module=true&tab=true&terms=true&ymms=false&classname= 1/5
LO None Medium-Low (M1) 2 & 3 Medium-High (M2) 1, 2 & 3 HI 1, 3 & 4 Fig 1: Identifying Blower Motor Switch Terminals Courtesy of FORD MOTOR CO. BLOWER MOTOR DOES NOT OPERATE 1. Check Blower Motor Operation Ensure engine is off and ignition is on. Set A/C-heater selector switch to FLOOR position. Set blower motor switch to HI position. If blower motor operates, go to next step. If blower motor does not operate, go to step 4). 2. Check Blower Motor At Low Speed Rotate blower motor switch to LO position. If blower motor does not operate, go to next step. If blower motor operates, wiggle wires and http://www2.prodemand.com/print/index?content=tabs&module=true&tab=true&terms=true&ymms=false&classname= 2/5
check for intermittent operation. Repair wire(s) as necessary. 3. Check Blower Motor Resistor Check blower motor resistor and thermal limiter for continuity. If continuity does not exist, replace blower motor resistor. If continuity exists, check for open in Black wire from blower motor switch to ground. Check Orange/Black wire between blower motor switch and blower motor for open or short to ground. Repair wire(s) as necessary. 4. Check Blower Motor Turn ignition off. Using jumper wire, ground Orange/Black wire at A/C-heater selector switch. Set A/C-heater selector switch to FLOOR position. Turn ignition on long enough to check blower motor operation. If blower motor does not operate, go to next step. If blower motor operates, check for open Orange/Black wire between blower motor and splice to blower switch and blower switch resistor. 5. Check Fuse Check blower motor fuse (30-amp). If fuse is okay, go to next step. If fuse is blown, go to step 9). 6. Check Supply Voltage Set A/C-heater selector switch to FLOOR position. Turn ignition on. Measure voltage of Brown/Orange wire at blower motor relay. If battery voltage does not exist, go to next step. If battery voltage exists, go to step 8). 7. Check A/C-Heater Selector Switch Pull integrated control panel from instrument panel enough to access harness connector. Disconnect A/C-heater selector switch connector. Set A/C-heater selector switch to FLOOR position. Check for continuity between Black and Yellow wires at switch connector terminals. If continuity exists, go to next step. If continuity does not exist, replace A/C-heater selector switch. 8. Check Blower Motor Relay Reinstall integrated control panel. Set A/C-heater selector switch to FLOOR position. Turn ignition on. Measure voltage of Dark Blue/Light Green wire at blower motor connector. If battery voltage exists, replace blower motor. If battery voltage does not exist, repair Dark Blue/Light Green wire between integrated control panel and blower motor. 9. Check Circuit Turn ignition off. Disconnect blower motor connector. Install new A/C fuse (15-amp). Set A/C-heater selector switch to FLOOR position. Turn ignition on. If fuse blows, go to next step. If fuse does not blow, replace blower motor. 10. Check Circuit For Short Pull integrated control panel from instrument panel enough to access harness connector. Disconnect A/C-heater selector switch connector. Set A/Cheater selector switch to FLOOR position. Install a new A/C fuse (15-amp). Turn ignition on. If the fuse blows, check Brown/Orange wire for short to ground. If fuse does not blow, check Dark Blue/Light Green wire for short to ground. Repair wire(s) as necessary. TEST F - BLOWER MOTOR DOES NOT RUN 1. Check Fuse Check power distribution fuse No. 9 (40-amp) in power distribution box (located on left side of engine compartment). If fuse is blown, go to next step. If fuse is not blown, go to step 4). 2. Check Circuit Turn ignition off. Disconnect connector from blower motor speed controller (located behind glove box). Replace fuse No. 9 (40-amp) in power http://www2.prodemand.com/print/index?content=tabs&module=true&tab=true&terms=true&ymms=false&classname= 3/5
distribution box. Turn ignition on. Measure voltage between Pink/White and Black wires at blower motor speed controller harness connector. If voltage is greater than 9 volts, go to next step. If voltage is less than 9 volts, check Pink/White and Black wires for open or high resistance. Repair wire(s) as necessary. Retest system. 3. Check Blower Motor Speed Controller Turn ignition off. Reconnect 5-pin harness connector. Turn ignition on. If fuse does not blow, go to next step. If fuse blows, check Orange/Black wire for short. Repair wire if necessary. If Orange/Black wire is okay, replace blower motor speed controller. Retest system. 4. Check Wiring Turn ignition off. Remove Orange/Black wire from blower motor speed controller harness connector. Turn ignition on. Press AUTO button. Press and hold FAN (+) button. If blower operates at high speed, go to next step. If blower does not operate at high speed, go to step 6). 5. Check For Open Circuit Check Orange/Black wire for open circuit between RCC module and blower motor speed controller. Wiggle wire during test. If wire is okay, replace RCC module. If wire is faulty, repair as necessary. Retest system. 6. Check Voltage With Orange/Black wire still disconnected, turn ignition on and press FAN (+) button. Check for voltage at blower motor speed controller harness connector. If voltage is greater than.5 volt, check blower motor. Replace motor if required. If voltage is less than.5 volt, replace blower motor speed controller. Retest system. TEST H - BLOWER MOTOR DOES NOT OPERATE AT LOWER SPEEDS 1. Check Voltage Stability Disconnect blower motor speed controller harness connector. Connect a 10,000 ohm resistor between Pink/White and Orange/Black wires at connector. Turn ignition on. Set blower motor speed halfway between high and low speed. Check voltage across resistor. Voltage range should be 0-5 volts and should not fluctuate. If voltage is as specified, go to next step. If voltage fluctuates, replace RCC module. Retest system. 2. Check Voltage With conditions the same as step 1), press and hold FAN (+) button while observing voltage reading. Voltage should increase. Press and hold FAN (-) button. Voltage should decrease. If voltage varies as specified, replace blower motor speed controller. If voltage does not vary as specified, replace RCC module. Retest system after repair. TEST J - BLOWER MOTOR DOES NOT OPERATE AT HIGH SPEED 1. Check Blower Operation Start engine, select MAX A/C, and set blower speed halfway between high and low speed. Verify that the blower operates. Press and hold FAN (+) button. If blower speed does not increase, go to next step. If blower speed increases, go to TEST A. 2. Check Input Voltage Turn ignition off. Disconnect harness connector from blower motor speed controller. Start engine. Press MAX A/C button. Press and hold FAN (+) button. Check voltage between Orange/Black wire and Black wires at blower motor speed controller harness connector. If less than 10 volts exist, go to next step. If greater than 10 volts exist, replace blower motor speed controller. Retest system. http://www2.prodemand.com/print/index?content=tabs&module=true&tab=true&terms=true&ymms=false&classname= 4/5
3. Check Voltage Start engine, select MAX A/C. Press and hold FAN (+) button to obtain full high speed. Measure voltage of Orange/Black wire between RCC module harness connector and ground. If voltage is 10 volts or greater, repair Orange/Black wire between RCC module and blower motor speed controller. If voltage is less than 10 volts, replace RCC module. Retest system. TEST K - COLD ENGINE BLOWER CONTROL DIAGNOSIS (NO DTC) 1. Check Cold Engine Blower Motor Operation Ensure engine coolant temperature is less than 120 F (49 C). Ensure EATC system is set at 90 F (32 C). Start engine, press AUTO button. If blower motor stays off for 3 1/2 minutes after engine start-up, go to next step. If blower motor does not operate as described, go to step 6). 2. Check Warm Engine Blower Motor Operation Allow engine to operate until blower speed increases from low speed. Note the amount of time elapsed before blower speed increases. If 3 1/2 minutes elapse before blower speed increases, go to next step. If blower speed increases before 3 1/2 minutes have elapsed, cold engine lockout function is inoperative. Go to TEST A. 3. Perform Self-Diagnostic Test Simultaneously depress OFF and FLOOR buttons, then press AUTO button within 2 seconds. Display will show a pulse tracer going around the center of the display window for up to 30 seconds while test is running. If DTC 115 is not displayed, go to next step. If DTC 115 is displayed, go to step 5). 4. Check Blower Motor Operation Press MAX A/C button. Turn ignition on. Set blower to high speed. If blower does not operate, go to step 1). If blower operates, replace RCC module. Retest system. 5. Check Engine Coolant Check engine coolant level. If coolant level is okay, go to next step. If coolant level is low, add coolant as required. Retest system. 6. Check Engine Coolant Temperature Signal Perform Powertrain Control Module (PCM) diagnostic procedures. See appropriate article in the ENGINE PERFORMANCE section. If PCM diagnostics indicate Engine Coolant Temperature (ECT) sensor malfunction, repair problem as necessary and go to step 1). If no malfunction is indicated, go to next step. 7. Check Cold Engine Lock-Out Circuits For Open Check for open circuit in Tan/Orange wire and Pink/Black wire in module communications network. If open circuit is found, repair circuit(s) as necessary or test module communications network. See the MODULE COMMUNICATIONS NETWORK article in the ACCESSORIES/SAFETY EQUIP section. If no open circuit is found, go to next step. 8. Check Cold Engine Lock-Out Circuits For Intermittent Open Wiggle Tan/Orange wire and Pink/Black wire in module communications network. If intermittent open is found, repair wire(s) as necessary or test module communications network. See the MODULE COMMUNICATIONS NETWORK article in the ACCESSORIES/SAFETY EQUIP section. If no intermittent open is found, replace RCC module. Retest system after repair. http://www2.prodemand.com/print/index?content=tabs&module=true&tab=true&terms=true&ymms=false&classname= 5/5