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Home › Lincoln › 2000 › Navigator RWD › Repair and Diagnosis › External Pages › Different car › Section 2 (A/C-Heater System - Automatic) › Self-Diagnostics › Test T: Temperature Control Does Not Operate Using Front/Rear Auxiliary Climate Controls

Test T: Temperature Control Does Not Operate Using Front/Rear Auxiliary Climate Controls

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. Verify System

    Turn ignition to run (engine off). Place front auxiliary blower switch in HI position. Rotate front auxiliary temperature control from COOL to WARM. If front auxiliary control operates properly, go to next step. If control does not operate properly, go to step 8)  .

  2. Test System For Normal Operation

    Place rear auxiliary blower motor switch in REAR position. Place rear blower switch in HI position. Rotate auxiliary temperature control from COOL to WARM. If rear auxiliary control operates properly, system is okay at this time. If control does not operate properly, go to next step.

  3. Check Yellow Wire Circuit

    Turn ignition off. Disconnect rear auxiliary blend potentiometer connector. Disconnect auxiliary climate control module connector. Measure resistance of Yellow wire between rear auxiliary potentiometer connector and auxiliary climate control module connector. Measure resistance of Yellow wire between auxiliary climate control module connector and ground. If resistances between connectors is less than 5 ohms and more than 10,000 ohms between connector and ground, go to next step. If resistances are not as specified, repair Yellow wire. Retest system.

  4. Check White Wire Circuit

    Disconnect auxiliary blend actuator connector. Measure resistance of White wire between rear auxiliary blend potentiometer connector and auxiliary blend actuator. If resistance is less than 5 ohms, go to next step. If resistance is more than 5 ohms, repair White wire. Retest system.

  5. Check Brown Wire Circuit

    Measure resistance of Brown wire between rear auxiliary blend potentiometer connector and auxiliary blend actuator connector. If resistance is less than 5 ohms, go to next step. If resistance is more than 5 ohms, repair Brown wire. Retest system.

  6. Check Rear Auxiliary Blend Potentiometer

    Measure resistance between Brown wire and Yellow wire terminals of rear auxiliary blend potentiometer connector. If resistance is between 4000-6000 ohms, go to next step. If resistance is not between 4000-6000 ohms, replace rear auxiliary blend potentiometer. Retest system.

  7. Check Rear Auxiliary Blend Potentiometer Wiper

    Measure resistance between Brown wire and White wire terminals of rear auxiliary blend potentiometer connector while rotating potentiometer. If resistance varies, replace auxiliary climate control module. Retest system. If resistance does not vary, replace rear auxiliary blend potentiometer. Retest system.

  8. Check Rear Auxiliary Temperature Control Operation

    Place front auxiliary blower motor switch in REAR position. Place rear blower switch in HI position. Rotate auxiliary temperature control from COOL to WARM. If rear temperature control operates properly, go to next step. If control does not operate properly, go to step 14)  .

  9. Check Red Wire Circuit

    Turn ignition off. Disconnect front auxiliary blend potentiometer connector. Disconnect auxiliary climate control module connector. Measure resistance of Red wire between front auxiliary potentiometer connector and auxiliary climate control module connector. Measure resistance of Red wire between auxiliary climate control module connector and ground. If resistances between connectors is less than 5 ohms and more than 10,000 ohms between connector and ground, go to next step. If resistances are not as specified, repair Red wire. Retest system.

  10. Check White Wire Circuit

    Disconnect auxiliary blend actuator connector. Measure resistance of White wire between front auxiliary blend potentiometer connector and auxiliary blend actuator. If resistance is less than 5 ohms, go to next step. If resistance is more than 5 ohms, repair White wire. Retest system.

  11. Check Front Auxiliary Potentiometer Brown Wire Circuit

    Measure resistance of Brown wire between front auxiliary blend potentiometer connector and auxiliary blend actuator connector. If resistance is less than 5 ohms, go to step 18)  . If resistance is more than 5 ohms, repair Brown wire. Retest system.

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  12. Check Front Auxiliary Blend Potentiometer

    Measure resistance between White wire and Red wire terminals of front auxiliary blend potentiometer connector. If resistance is between 4000-6000 ohms, go to next step. If resistance is not between 4000-6000 ohms, replace front auxiliary blend potentiometer. Retest system.

  13. Check Front Auxiliary Blend Potentiometer Wiper

    Measure resistance between Brown wire and White wire terminals of front auxiliary blend potentiometer connector while rotating potentiometer. If resistance varies, replace auxiliary climate control module. Retest system. If resistance does not vary, replace front auxiliary blend potentiometer. Retest system.

  14. Check Voltage To Auxiliary Blend Actuator

    Turn ignition off. Disconnect auxiliary blend actuator connector. Measure voltage of White/Light Blue wire between auxiliary blend actuator connector and ground. If voltage is more than 10 volts, go to next step. If voltage is less than 10 volts, repair White/Light Blue wire. Retest system.

  15. Check Black Wire Circuit For Open

    Measure resistance of Black wire between auxiliary blend actuator connector and ground. If resistance is less than 5 ohms, go to next step. If resistance is more than 5 ohms, repair Black wire. Retest system.

  16. Check Light Blue Wire Circuit

    Measure resistance of Light Blue wire between auxiliary blend actuator connector and auxiliary climate control module connector. Measure resistance of Light Blue wire between auxiliary blend actuator connector and ground. If resistances between connectors is less than 5 ohms and more than 10,000 ohms between connector and ground, go to next step. If resistances are not as specified, repair Light Blue wire. Retest system.

  17. Check White Wire Circuit

    Disconnect front auxiliary Blend potentiometer connector. Disconnect rear auxiliary blend potentiometer connector. Measure resistance of White wire between auxiliary blend actuator connector and rear auxiliary blend potentiometer connector. Measure resistance of White wire between auxiliary blend actuator connector and ground. If resistances between connectors is less than 5 ohms, and more than 10,000 ohms between connector and ground, go to next step. If resistances are not as specified, repair White wire. Retest system.

  18. Check Brown Wire Circuit

    Measure resistance of Brown wire between auxiliary blend actuator connector and rear auxiliary blend potentiometer connector. Measure resistance of Brown wire between auxiliary blend actuator connector and ground. If resistances between connectors is less than 5 ohms and more than 10,000 ohms between connector and ground, go to next step. If resistances are not as specified, repair Brown wire. Retest system.

  19. Check Yellow Wire Circuit For Short

    Measure resistance of Yellow wire between auxiliary climate control module connector and ground. If resistance is less than 5 ohms, go to next step. If resistance is more than 5 ohms, repair Yellow wire. Retest system.

  20. Check Red Wire For Short

    Measure resistance of Red wire between auxiliary climate control module connector and ground. If resistance is more than 10,000 ohms, go to next step. If resistance is less than 10,000 ohms, repair Red wire. Retest system.

  21. Check Auxiliary Blend Actuator

    Reconnect auxiliary blend actuator connector. Turn ignition to run (engine off). Place front auxiliary blower switch in HI position. Connect jumper wire between White/Light Blue wire and Light Blue wire terminals of auxiliary climate control module connector. If auxiliary blend actuator operates, replace auxiliary climate control module. Retest system. If actuator does not operate, go to next step.

  22. Check Auxiliary Blend Actuator

    Connect jumper wire between Black wire and Light Blue wire terminals of auxiliary climate control module connector. If auxiliary blend actuator operates, replace auxiliary climate control module. Retest system. If actuator does not operate, replace auxiliary blend actuator. Retest system.
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