LEMON Manuals: Even more car manuals for everyone
Home >> Chevrolet >> 2002 >> Blazer 4D Utility, 4WD, Part Time >> Repair and Diagnosis >> External Pages >> Different car >> Section 40 (HVAC Systems - Manual) >> Symptom Tests >> Test I: Blower Motor Malfunction (Auxiliary) >> Models Without Sunroof

Models Without Sunroof

WARNING: This page does not describe the selected car, but rather 7 other vehicles, including the 2002 GMC Yukon XL, 2002 GMC Yukon, 2002 Chevrolet Tahoe, 2002 Chevrolet Suburban, and 2002 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.
  1. Perform SYSTEM OPERATION CHECK  under TROUBLE SHOOTING. Go to next step.
    2. NOTE: This step will determine if one or more blower speeds are inoperative.
    NOTE: The rear auxiliary HVAC control assembly will only function if the front auxiliary blower motor switch is placed in the REAR position.
  2. Turn ignition on. Operate the auxiliary blower motor in each speed position from both the front and rear auxiliary HVAC control assemblies. Does the auxiliary blower motor operate correctly in each speed position from both the front and rear auxiliary HVAC control assemblies? If so, check for intermittent and poor connections. If not, go to next step.
    3. NOTE: If the auxiliary blower motor operates correctly from the rear auxiliary HVAC control assembly, the auxiliary blower motor and auxiliary blower motor resistor assembly are functioning properly.
  3. Set the front auxiliary blower motor switch to enable the rear auxiliary HVAC control assembly. Place the rear auxiliary blower motor switch in each speed position. Does the auxiliary blower motor operate in each speed position? If so, go to step  8. If not, go to next step.
    4. NOTE: This step tests for an open in one of the blower motor speed control circuits and determines if the auxiliary blower motor and auxiliary blower motor resistor are functioning correctly.
  4. Place the front auxiliary blower motor switch in each speed position. Does the auxiliary blower motor operate in each speed position? If so, go to step  9. If not, go to next step.
  5. Turn ignition off. Disconnect the auxiliary blower motor connector. Turn ignition on. Connect a test light between the auxiliary blower motor supply circuit and the auxiliary blower motor ground circuit. Place the auxiliary blower motor switch in each speed position. Does the test light illuminate and change intensity in each speed position? If so, go to step  17. If not, go to next step.
    6. NOTE: The auxiliary blower motor switch must be in the correct position for the auxiliary blower motor speed control circuit being tested. Failure to do this will result in a misdiagnosis.
  6. Turn ignition off. Disconnect the auxiliary blower motor resistor assembly connector C1. Probe each auxiliary blower motor speed control circuit with a test light that is connected to battery positive voltage. Place the front auxiliary blower motor switch in each speed position for the auxiliary blower motor speed control circuit being tested. Does the test light illuminate in each position? If so, go to step  18. If not, go to next step.
  7. Check the appropriate auxiliary blower motor speed control circuit for an open or high resistance between the auxiliary blower motor resistor assembly and the rear auxiliary HVAC control assembly. Did you find and correct the condition? If so, go to step  24. If not, go to step  14.
  8. Check each auxiliary blower motor speed control circuit for an open or high resistance between the front auxiliary HVAC control assembly and the rear auxiliary HVAC control assembly. Did you find and correct the condition? If so, go to step  24. If not, go to step  15.
  9. Turn ignition off. Disconnect the front auxiliary HVAC control assembly. Turn ignition on. Place the rear auxiliary blower motor switch in the maximum speed position. Connect a 3 amp fused jumper wire between the rear auxiliary enable control circuit and the front auxiliary HVAC control assembly ground circuit. Does the auxiliary blower motor operate? If so, go to step  15. If not, go to next step.
  10. Is the vehicle equipped with auxiliary heat and A/C? If so, go to step  12. If not, go to next step.
  11. Check the rear auxiliary enable control circuit for an open or high resistance. Did you find and correct the condition? If so, go to step  24. If not, go to step  14.
  12. Turn ignition off. Disconnect the auxiliary HVAC control processor. Turn ignition on. Connect a 3 amp fused jumper wire between auxiliary blower motor control circuit and the auxiliary HVAC control processor ground circuit. Does the auxiliary blower motor operate? If so, go to step  16. If not, go to next step.
  13. Check auxiliary blower motor control circuit for an open or high resistance. Did you find and correct the condition? If so, go to step  24. If not, go to next step.
  14. Inspect rear auxiliary HVAC control assembly harness connector for poor connections. Did you find and correct the condition? If so, go to step  24. If not, go to step  19.
  15. Inspect front auxiliary HVAC control assembly harness connector for poor connections. Did you find and correct the condition? If so, go to step  24. If not, go to step  22.
  16. Inspect auxiliary HVAC control processor harness connector for poor connections. Did you find and correct the condition? If so, go to step  24. If not, go to step  23.
  17. Inspect auxiliary blower motor harness connector for poor connections. Did you find and correct the condition? If so, go to step  24. If not, go to step  20.
  18. Inspect auxiliary blower motor resistor assembly harness connectors for poor connections. Did you find and correct the condition? If so, go to step  24. If not, go to step  21.
  19. Replace the rear auxiliary HVAC control assembly. See HVAC CONTROL ASSEMBLY (REAR AUXILIARY)  under REMOVAL & INSTALLATION. After repairs are complete, go to step  24.
  20. Replace the auxiliary blower motor. See BLOWER MOTOR (AUXILIARY)  under REMOVAL & INSTALLATION. After repairs are complete, go to step  24.
  21. Replace the auxiliary blower motor resistor assembly. See BLOWER MOTOR RESISTOR (AUXILIARY)  under REMOVAL & INSTALLATION. After repairs are complete, go to step  24.
  22. Replace the front auxiliary HVAC control assembly. See HVAC CONTROL ASSEMBLY (FRONT AUXILIARY)  under REMOVAL & INSTALLATION. After repairs are complete, go to step  24.
  23. Replace the auxiliary HVAC control processor. See HVAC CONTROL PROCESSOR (AUXILIARY)  under REMOVAL & INSTALLATION. After repairs are complete, go to next step.
  24. Operate the system in order to verify the repair. Did you correct the condition? If so, system is okay. If not, go to step  2.
scientia non olet · About LEMON Manuals