J: A/C CLUTCH INOPERATIVE
PINPOINT TEST J: A/C CLUTCH INOPERATIVEJ1 CHECK SYSTEM OPERATION
NOTE: The ambient temperature must be above approximately 10°C (50°F) for A/C compressor operation.
- Start engine.
- Turn A/C on.
- Check battery voltage (if not 12.5 V or more, refer to Starting and Charging Systems/Charging System/Testing and Inspection for charging system diagnosis). Testing and Inspection
- Turn blower motor switch to HI.
- Does A/C clutch engage after 5 second delay?
- YES
Circuit functioning properly.
- NO
Go to J2.
J2 A/C CYCLING SWITCH
- Disconnect electrical connector from A/C cycling switch.
- Jumper harness pins.
- Engine must be running with A/C on.
- Does A/C clutch engage?
- YES
Go to J3.
- NO
Go to J4.
J3 CHECK REFRIGERANT SYSTEM PRESSURE
- Connect gauge set to service ports and observe pressure.
- Reading should be above 344.75 kPa (50 psi) with the engine off.
- Is pressure above 344.75 kPa (50 psi)?
- YES
Replace A/C cycling switch.
- NO
Check refrigerant system for leaks. Service system as required. Go to J1.
J4 CHECK VOLTAGE AT A/C CYCLING SWITCH
- Check for battery positive voltage (B+) at the A/C cycling switch electrical connector Circuit 345 (P) (Crown Victoria/Grand Marquis), Circuit 883 (PK/LB) (Town Car) to ground.
- Check for B+ at A/C high pressure cutout switch electrical connector Circuit 883 (PK/LB) (Crown Victoria/Grand Marquis), Circuit 441 (R/Y) (Town Car) to ground.
- Is there B+?
- YES
Go to J7.
- NO
Go to J5.
J5 CHECK A/C CONTROL ASSEMBLY
- Check for B+ at A/C control assembly Circuit 348 (P) (Crown Victoria/Grand Marquis), Circuit 583 (PK/LB) (Town Car) to ground.
- Is there B+?
- YES
Service wiring as necessary. Go to J1.
- NO
Go to J6.
J6 CHECK A/C CONTROL SUPPLY VOLTAGE
- Check for B+ at A/C control assembly Circuit 294 (W/LB) (Crown Victoria/Grand Marquis), Circuit 298 (P/O) (Town Car) to ground.
- Ignition switch must be in the RUN position.
- Is there B+?
- YES
Replace A/C control assembly. Go to J1.
- NO
Service wiring for opens or shorts. Check fuse, if blown, check clutch diode for short. Service as necessary. Go to J1.
J7 CHECK A/C CLUTCH CIRCUITS
- Check for voltage across harness connector at A/C clutch field coil.
- A minimum of 10 volts is required.
- Is there a minimum of 10 volts?
- YES
Go to J9.
- NO
Go to J8.
J8 CHECK A/C CLUTCH VOLTAGE
- Check for voltage at A/C clutch harness Circuit 347 (BK/Y) (Crown Victoria/Grand Marquis), Circuit 348 (P) (Town Car) and ground.
- Is there a minimum of 10 volts?
- YES
Go to J11.
- NO
Go to J12.
J9 JUMP A/C CLUTCH FIELD COIL
- Disconnect A/C clutch field coil and jump B+ and ground to A/C clutch field coil.
- Does A/C clutch engage?
- YES
Clean coil electrical terminals and retest system.
- NO
Go to J10.
J10 CHECK A/C CLUTCH AIR GAP
- Check air gap between A/C clutch and A/C clutch pulley. Air gap must be within specified limits. Refer to Heating and Air Conditioning/Compressor HVAC/Specifications. Specifications
- Is the air gap within specifications?
- YES
Replace A/C clutch field coil.
- NO
Reset air gap. Go to J9.
J11 CHECK A/C CLUTCH GROUND
- Check Circuit 57 (BK) at clutch harness connector for continuity to ground. Must have continuity with minimum resistance.
- Is there continuity?
- YES
Check ground connection. Clean as necessary. Go to J1.
- NO
Service circuit and/or connection.
J12 CHECK VOLTAGE AT A/C CUTOUT RELAY
- Check for B+ at the A/C cutout relay Circuit 198 (DG/O) (Crown Victoria/Grand Marquis), 347 (BK(Y) (Town Car) to ground.
- Is there voltage?
- YES
Go to J14.
- NO
Go to J13.
J13 CHECK VOLTAGE AT A/C PRESSURE CUT-OFF SWITCH
- Check for B+ at the A/C pressure cut-off switch Circuit 198 (DG/O) (Crown Victoria/Grand Marquis), 347 (BK/Y) (Town Car) to ground.
- Is there voltage?
- YES
Service circuit 198 (DG/O) or 347 (BK/Y). Go to J1
- NO
Replace A/C pressure cut-off switch. Go to J1.
J14 CHECK A/C CUTOUT RELAY
- Disconnect connector from relay.
- Jumper across the connector Circuit 198 (DG/O) (Crown Victoria/Grand Marquis), Circuit 347 (BK(Y) (Town Car) to 347 (BK/Y) (Crown Victoria, Grand Marquis), 348 (P) (Town Car).
- With engine running and A/C on, check for A/C clutch engagement.
- Does A/C clutch engage?
- YES
Go to J15
- NO
Check for shorted diode or open circuit 347 (BK/Y) (Crown Victoria/Grand Marquis), 348 (P) (Town Car).
J15 CHECK A/C CUTOUT RELAY OPERATION
- With the engine running, reconnect the harness connector to the A/C cutout relay and check to see if relay energizes. The A/C clutch circuit will open if the relay energizes.
- Does relay energize?
- YES
The powertrain control module is causing relay to energize and interrupt A/C compressor circuit. Any of the following can be the cause. Refer to Powertrain Management/Computers and Control Systems/Testing and Inspection for additional information. Testing and Inspection
Throttle position sensor sending wide open throttle signal to powertrain control module. Disconnect electrical connector to remove throttle position sensor from circuit. A/C clutch will engage if throttle position sensor is sending wide open throttle cutout signal.
Engine coolant temperature sensor sending hot coolant signal to powertrain control module. Disconnect electrical connector from engine coolant temperature sensor.
A/C clutch will engage if engine coolant temperature sensor is sending hot coolant signal to the powertrain control module. A/C ON circuit to powertrain control module open. If circuit is open, powertrain control module will not receive signal from A/C pressure cut-off switch to turn A/C clutch on.
- NO
Replace A/C cutout relay.