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 31 (HVAC Systems - Manual) >> Symptom Tests >> Test O: Too Cold In Vehicle

Test O: Too Cold In Vehicle

WARNING: This page is about a different car, the 2002 GMC Savana Special, 2002 GMC Savana Camper Special, 2002 GMC Savana, and 2002 Chevrolet Chevy Express. However, it is still accessible from the selected car via links, so may be relevant.
NOTE: For circuit reference, see CONNECTOR IDENTIFICATION  and/or WIRING DIAGRAMS  .
NOTE: Definition: Temperature can not be adjusted or heating insufficient.
  1. If review of system operation has been performed, go to next step. If review of system operation has not been performed, see DESCRIPTION  and OPERATION  . Review HVAC operation and perform visual inspection of system. See OPERATION . If system inspection and review of operation has been performed, go to next step.
  2. Turn ignition on. Place mode switch in any position except off. Place blower switch in each speed position. If blower motor operates in any speed position, go to next step. If blower motor does not operate in any speed position, go to TEST E: BLOWER MOTOR INOPERATIVE .
  3. If blower motor operates correctly in each speed position, go to next step. If blower motor does not operate correctly in each speed position, go to TEST F: BLOWER MOTOR MALFUNCTION .
  4. Ensure blower switch is on. Select an air outlet mode. If air flows out the selected outlet, go to next step. If air does not flow out the selected outlet, go to TEST A: AIR DELIVERY IMPROPER .
  5. Check cooling system for low coolant level, loose or worn accessory drive belt, leaking radiator or heater hoses, kinked radiator hose or heater hose, missing radiator cap pressure seal, and a leaking radiator cap. If any of these conditions were found, repair as necessary and go to step  17. If none of these conditions were found, go to next step.
  6. Start engine. Place mode switch in BI-LEVEL position. If A/C compressor operates, go to TEST K: COMPRESSOR CLUTCH DOES NOT DISENGAGE . If A/C compressor does not operate, go to next step.
  7. While placing air temperature switch from coldest position to warmest position, observe air temperature actuator drive shaft. If air temperature actuator drive shaft rotates at all, go to next step. If air temperature drive shaft does not rotate at all, go to step  9.
  8. Check air temperature door for misaligned actuator, broken or binding door and/or linkage, obstructions preventing door from operating within its' full range, missing and/or misaligned door seals. If a door condition was found, repair as necessary and go to step  17. If a door condition was not found, go to next step.
  9. Check ignition 3 voltage circuit (Brown wire) of air temperature door actuator for an open or high resistance. See WIRING DIAGRAMS . If an open or high resistance was found, repair as necessary and go to step  17. If an open or high resistance was not found, go to next step.
  10. Check ground circuit (Black wire) of air temperature door actuator for an open or high resistance. See WIRING DIAGRAMS . If an open or high resistance was found, repair as necessary and go to step  17. If an open or high resistance was not found, go to next step.
  11. Check air temperature door position signal circuit (Light Blue wire) for an open, high resistance, a short to ground, or a short to voltage. See WIRING DIAGRAMS . If a circuit problem was found, repair as necessary and go to step  17. If a circuit problem was not found, go to next step.
  12. Ensure HVAC control assembly is properly connected. Turn ignition on. Using a DVOM, measure voltage between air temperature door control circuit (Light Blue wire) and ground, while placing air temperature switch from coldest position to warmest position. See WIRING DIAGRAMS . If voltage ranges from zero-12 volts, with a smooth transition between COLD and HOT position, go to step  14. If voltage does not range from zero-12 volts, with a smooth transition between COLD and HOT position, go to next step.
  13. Check harness connector at air temperature actuator for a poor connection. If a poor connection was found, repair as necessary and go to step  17. If a poor connection was not found, go to step  15.
  14. Check harness connector at HVAC control assembly for a poor connection. If a poor connection was found, repair as necessary and go to step  17. If a poor connection was not found, go to step  16.
  15. Replace air temperature door actuator. See ACTUATORS  under REMOVAL & INSTALLATION. After repairs are complete, go to step  17.
  16. Replace main HVAC control assembly. See MAIN HVAC CONTROL ASSEMBLY  under REMOVAL & INSTALLATION. If replacement is complete, go to next step.
  17. Operate system to verify repair. If the condition was corrected, system is okay. If the condition was not corrected, return to step  2.
scientia non olet · About LEMON Manuals