LEMON Manuals: Even more car manuals for everyone
Home >> Ford >> 2000 >> Expedition 5.4 L, RWD >> Repair and Diagnosis >> External Pages >> Different car >> Section 2 (A/C-Heater System - Automatic) >> Self-Diagnostics >> Test D: A/C Does Not Operate Or Does Not Operate Properly

Test D: A/C Does Not Operate Or Does Not Operate Properly

WARNING: This page is about a different car, the 1999 Lincoln Navigator and 1999 Ford Expedition. However, it is still accessible from the selected car via links, so may be relevant.

  1. Check PID WACF With A/C Off

    Ensure ambient temperature is above 50°F (10°C). Turn ignition to run position (engine off). Turn EATC system to OFF. Perform PCM Parameter Identification WOT A/C Primary Circuit Fault (PID WACF) test. If PID WACF reads YES, perform PCM self-diagnostics test. See appropriate SELF-DIAGNOSTICS article in ENGINE PERFORMANCE. If PID WACF does not read YES, go to next step.
    NOTE: If PID WACF reads YES, this is the same fault as DTC P1460.

  2. Check PID WACF With A/C On

    Start engine and run at idle. Set EATC system to MAX A/C position. Perform PCM PID WACF. If PID WACF reads YES, perform PCM self-diagnostics test. See appropriate SELF-DIAGNOSTICS article in ENGINE PERFORMANCE. If PID WACF does not read YES, go to next step.

  3. Check PID ACCS With A/C On

    Run engine at idle. Set EATC system to MAX A/C position. Perform PCM Parameter Identification A/C Cycling Switch (PID ACCS) input. If PID ACCS reads ON, go to next step. If PID ACCS does not read ON, go to step 5)  .

  4. Check PID ACCS With A/C On

    Set EATC system to MAX A/C position. Perform PCM PID ACCS. If PID ACCS reads ON, go to step 15)  . If PID ACCS does not read ON, perform PCM self-diagnostics test. See appropriate SELF-DIAGNOSTICS article in ENGINE PERFORMANCE.

  5. Check Power Input To PCM

    Turn ignition off. Disconnect PCM 104-pin Gray harness connector (C174). Connect Breakout Box (014-00950) to PCM harness connector. DO NOT connect to PCM. Turn ignition to run (engine off). Set EATC panel to MAX A/C position. Using voltmeter, measure voltage at breakout box pin No. 41. If voltage is more than 10 volts, replace PCM. Retest system. If voltage is less than 10 volts, go to next step.

  6. Check Refrigerant System Pressure

    Turn ignition off. Connect manifold gauge set. If refrigerant system pressure is 50-250 psi (3.5-17.6 kg/cm2 ), go to next step. If refrigerant system pressure is not 50-250 psi (3.5-17.6 kg/cm2 ), leak test system. Repair as necessary. Retest system.

  7. Check Violet Wire Circuit For Open

    Disconnect EATC module harness connector. Disconnect A/C pressure cut-off switch harness connector. Using ohmmeter, measure resistance of Violet wire between cut-off switch and EATC module. If resistance is less than 5 ohms, go to next step. If resistance is more than 5 ohms, repair open in Violet wire. Retest system.

  8. Check Violet Wire Circuit For Short To Ground

    Measure resistance of Violet wire between cut-off switch connector and ground. If resistance is more than 10,000 ohms, go to next step. If resistance is less than 10,000 ohms, repair short to ground in Violet wire. Retest system.

  9. Check A/C Pressure Cut-Off Switch Voltage

    Reconnect EATC module connector. Turn ignition to run (engine off). Set EATC panel to MAX A/C position. Measure voltage of Violet wire between cut-off switch connector and ground. If voltage is more than 10 volts, go to next step. If voltage is less than 10 volts, replace EATC module. Retest system.

  10. Check Red/Yellow Wire Circuit For Short

    Disconnect A/C cycling switch harness connector. Measure resistance of Red/Yellow wire between cycling switch and ground. If resistance is more than 10,000 ohms, go to next step. If resistance is less than 10,000 ohms, repair short in Red/Yellow wire. Retest system.

  11. Check Red/Yellow Wire Circuit For Open

    Measure resistance of Red/Yellow wire between cycling switch connector and pressure cut-off switch connector. If resistance is less than 5 ohms, go to next step. If resistance is more than 5 ohms, repair open in Red/Yellow wire. Retest system.

  12. Check Voltage At A/C Cycling Switch

    Turn ignition off. Reconnect A/C cycling switch connector. Turn ignition to run (engine off). Measure voltage of Red/Yellow wire between A/C cycling switch connector and ground. If voltage is more than 10 volts, go to next step. If voltage is less than 10 volts, replace pressure cut-off switch. Retest system.

  13. Check Black/Yellow Wire Circuit For Short

    Turn ignition off. Measure resistance of Black/Yellow wire between cycling switch connector and ground. If resistance is more than 10,000 ohms, go to next step. If resistance is less than 10,000 ohms, repair short to ground in Black/Yellow wire. Retest system.

  14. Check Black/Yellow Wire Circuit For Open

    Measure resistance of Black/Yellow wire between A/C cycling switch connector and breakout box pin No. 41. If resistance is less than 5 ohms, replace cycling switch. Retest system. If resistance is more than 5 ohms, repair open in Black/Yellow wire. Retest system.

  15. Check Light Blue/Pink Wire Circuit For Short

    Turn ignition off. Disconnect A/C Wide Open Throttle (WOT) relay harness connector (located in battery junction box, in engine compartment). Remove fuse No. 5 (15-amp) from passenger compartment fuse block. Measure resistance of Light Blue/Pink wire between relay connector and ground. If resistance is less than 10,000 ohms, repair short to ground in Light Blue/Pink wire. If resistance is more than 10,000 ohms, go to next step.

  16. Check Light Blue/Pink Wire Circuit For Open

    Turn ignition to run (engine off). Measure voltage of Light Blue/Pink wire between WOT relay connector and ground. If voltage is more than 10 volts, go to next step. If voltage is less than 10 volts or less, repair open in Light Blue/Pink wire. Retest system.

  17. Check A/C Clutch Relay

    Turn ignition off. Reconnect WOT relay connector. Disconnect A/C clutch coil connector. Turn ignition to run (engine off). Check fuse No. 5 (15-amp) in fuse block. If fuse is blown, go to next step. If fuse is okay, go to step 21)  .

  18. Check Gray/White Wire Circuit For Short

    Turn ignition off. Disconnect A/C WOT relay harness connector. Measure resistance of Gray/White wire between relay connector and ground. If resistance is more than 10,000 ohms, go to next step. If resistance is less than 10,000 ohms, replace relay. Retest system.

  19. Check A/C Clutch Diode

    Disconnect A/C clutch diode harness connector (located in battery junction box, in engine compartment). Measure resistance of Gray/White wire between relay connector and ground. If resistance is less than 10,000 ohms, repair short in Gray/White wire. Retest system. If resistance is more than 10,000 ohms, replace A/C clutch diode.

  20. Check A/C Clutch Input

    Turn ignition off. Reconnect A/C WOT relay. Disconnect A/C clutch coil harness connector. Turn ignition to run (engine off). Using New Generation Star Tester (007-00500), place tester in ACTIVE COMMAND MODE. Command PCM outputs ON. Measure voltage of Gray/White wire between A/C clutch oil connector and ground. If voltage is more than 10 volts, go to step 22)  . If voltage is less than 10 volts, go to next step.

  21. Check Gray/White Wire Circuit For Open

    Turn ignition off. Disconnect A/C WOT relay harness connector. Measure resistance of Gray/White wire between relay connector and A/C clutch coil connector. If resistance is less than 5 ohms, replace WOT relay. Retest system. If resistance is more than 5 ohms, repair open in Gray/White wire. Retest system.

  22. Check Black Wire Circuit For Open

    Turn ignition off. Measure resistance of Black wire between A/C WOT relay connector and ground. If resistance is less than one ohm, replace A/C clutch coil. Retest system. If resistance is more than one ohm, repair open in Black wire. Retest system.
scientia non olet · About LEMON Manuals