LEMON Manuals: Even more car manuals for everyone
Home >> GMC >> 2000 >> C3500 HD 6.5 F, Standard >> Repair and Diagnosis >> Heating, Ventilation & A/C (HVAC) >> HVAC Control Systems >> HVAC System - Manual - Escalade, Pickup, TAHOE & YUKON >> Trouble Shooting >> A/C Compressor Clutch Does Not Engage >> Except Diesel

Except Diesel

  1. Ensure A/C system has sufficient refrigerant charge. If refrigerant charge is sufficient, go to next step. If refrigerant charge is not sufficient, see CHARGING A/C SYSTEM in GENERAL SERVICING PROCEDURES article.
  2. Disconnect Vehicle Control Module (VCM) connector C3. Connect fused jumper between VCM connector C3 terminal No. 1 (Dark Green/White wire) and ground. Turn ignition switch to ON position. Listen for an audible click from A/C compressor clutch. If clutch clicks, go to step  14. If clutch does not click, go to next step.
  3. Remove A/C Compressor Clutch Relay. Connect fused jumper wire between A/C compressor clutch relay connector terminals B4 (Orange wire) and A6 (Dark Green wire). If clutch clicks, go to next step. If clutch does not click, go to step  7.
  4. Disconnect VCM connector C3. Connect fused jumper between A/C compressor clutch relay connector terminals A4 (Pink wire) and B6 (Dark Green/White wire). Using DVOM, measure voltage between VCM connector C3 terminal No. 1 (Dark Green/White wire) and ground. Turn ignition switch to ON position. If battery voltage is present, go to next step. If battery voltage is not present, go to step  6.
  5. Replace A/C compressor clutch relay. After repairs, recheck system operation.
  6. Repair open in Dark Green/White wire between A/C compressor clutch relay and VCM. After repairs, recheck system operation.
  7. Disconnect A/C compressor clutch connector. Using DVOM, check continuity between A/C compressor clutch connector terminal "A" and ground. If continuity is present, go to step  9. If continuity is not present, go to next step.
  8. Repair open in Black wire between compressor clutch and ground. After repairs, recheck system operation.
  9. Connect fused jumper between A/C compressor clutch relay connector terminals B4 (Orange wire) and A6 (Dark Green wire). Using DVOM, measure voltage between A/C compressor clutch connector terminals. If battery voltage is present, go to step  11. If battery voltage is not present, go to next step.
  10. Repair open in Dark Green wire between A/C compressor clutch relay and compressor clutch connector. After repairs, recheck system operation.
  11. Remove fused jumper between A/C compressor clutch relay connector terminals B4 and A6. Using DVOM, check continuity between A/C compressor clutch connector terminals. Reverse leads between terminals of connector. If continuity is present in one direction only, go to step  13. If continuity is not present in one direction only, go to next step.
  12. Replace diode located within A/C compressor clutch harness. After repairs, recheck system operation.
  13. Replace A/C Compressor Clutch. See appropriate COMPRESSOR SERVICING article in GENERAL SERVICING. After repairs, recheck system operation.
  14. Using DVOM, measure voltage between VCM connector C3 terminal No. 25 (Dark Green/White wire) and ground. Turn ignition switch to ON position. Rotate front blower switch to any of the speed positions. Push in A/C button. If battery voltage is present, go to next step. If battery voltage is not present, go to step  18.
  15. Disconnect A/C compressor cycling switch. Connect jumper wire between A/C compressor cycling switch connector terminals. Using DVOM, check continuity between VCM connector C3 terminal No. 30 and ground. If continuity is present, go to step  17. If continuity is not present, go to next step.
  16. Repair open in Dark Green wire or Black/White wire between VCM and ground. After repairs, recheck system operation.
  17. Replace A/C compressor cycling switch. After repairs, recheck system operation.
  18. Disconnect A/C high pressure switch connector. Connect fused jumper between A/C high pressure switch connector terminals. Using DVOM, measure voltage between VCM connector C3 terminal No. 25 and ground. Turn ignition switch to ON position. Rotate front blower switch to any of the speed positions. Push in A/C button. If battery voltage is present, go to next step. If battery voltage is not present, go to step  20.
  19. Replace A/C high pressure switch. After repairs, recheck system operation.
  20. Disconnect HVAC control module connector C3. Connect fused jumper between HVAC connector C3 terminals No. 5 (Brown wire) and No. 10 (Light Green wire). Using DVOM, measure voltage between VCM and ground. Turn ignition switch to ON position. Rotate front blower switch to any of the speed positions. Push in A/C button. If battery voltage is present, go to next step. If battery voltage is not present, go to step  22.
  21. Replace HVAC control module. See A/C-HEATER CONTROL ASSEMBLY  under REMOVAL & INSTALLATION. After repairs, recheck system operation.
  22. Repair open in Light Green wire or Dark Green/White wire between VCM and HVAC control module. After repairs, recheck system operation.
scientia non olet · About LEMON Manuals