LEMON Manuals: Even more car manuals for everyone
Home >> GMC >> 2000 >> Envoy >> Repair and Diagnosis >> External Pages >> Different car >> Section 3 (HVAC System - Manual) >> Trouble Shooting >> Temperature Control Inoperative >> 2000 Models

2000 Models

WARNING: This page does not describe the selected car, but rather 10 other vehicles, including the 2001 Oldsmobile Bravada, 2001 GMC Sonoma, 2001 GMC Jimmy, 2001 Chevrolet S10 Pickup, and 2001 Chevrolet Blazer. However, it is still accessible from the selected car via links, so may be relevant.
  1. Perform BLOWER CONTROLS SYSTEM CHECK . Go to next step.
  2. Check HVAC I fuse (10-amp) located in instrument panel fuse block. If fuse is blown, go to step  21. If fuse is okay, go to next step.
  3. Disconnect air temperature valve sensor and motor connector. Air temperature valve is located on top of HVAC assembly, on passenger's side. Turn ignition switch to ON position. Turn headlight switch to PARK position. Using DVOM connected to ground, probe air temperature valve motor harness connector terminal No. 8 (Light Blue wire). See WIRING DIAGRAMS . Move temperature control knob on A/C-heater control panel to hot (Red) and cold (Blue) positions. If voltage reading varies smoothly between zero and 12 volts, go to next step. If voltage reading does not vary smoothly between zero and 12 volts, go to step  9.
  4. Using DVOM connected to ground, measure voltage at air temperature valve motor harness connector terminal No. 10 (Brown wire). If battery voltage is indicated, go to next step. If battery voltage is not indicated, go to step  7.
  5. Using DVOM, measure voltage between air temperature valve motor harness connector terminals No. 10 (Brown wire) and No. 7 (Black wire). If battery voltage exists, go to next step. If battery voltage does not exist, go to step  8.
  6. Replace air temperature valve motor. See AIR TEMPERATURE VALVE ACTUATOR  under REMOVAL & INSTALLATION. Perform BLOWER CONTROLS SYSTEM CHECK .
  7. Repair open or high resistance in Brown wire between instrument panel fuse block HVAC I fuse and air temperature valve actuator. Perform BLOWER CONTROLS SYSTEM CHECK .
  8. Repair open or high resistance in Black wire between air temperature valve actuator and ground G200. Ground G200 is located on firewall, left of instrument panel, near main harness connector to engine compartment. Perform BLOWER CONTROLS SYSTEM CHECK .
  9. If voltage reading is at or near battery voltage, regardless of temperature control knob position, go to next step. If voltage reading is not at or near battery voltage, regardless of temperature control knob position, go to step  15.
  10. Disconnect A/C-heater control panel 3-pin harness connector C-3. Use a DVOM to measure voltage between A/C-heater control panel 3-pin harness connector C-3 terminals "A" (Brown wire) and "C" (Black wire). Turn ignition switch to ON position. Turn headlight switch to PARK position. If battery voltage is indicated, go to next step. If battery voltage is not indicated, go to step  12.
  11. Replace A/C-heater control panel. See A/C-HEATER CONTROL PANEL  under REMOVAL & INSTALLATION. Perform BLOWER CONTROLS SYSTEM CHECK .
  12. Move headlight switch to OFF position. If DVOM reading changes to battery voltage, go to next step. If DVOM reading does not change to battery voltage, go to step  14.
  13. Repair high resistance in Black wire between splice pack SP203 and ground G203. SP203 is strapped to instrument panel harness, in front of ashtray. Ground G203 is located in body harness, to right of instrument panel, on firewall below air inlet. Perform BLOWER CONTROLS SYSTEM CHECK .
  14. Repair open or high resistance in Black wire between A/C-heater controller and splice pack SP203. Perform BLOWER CONTROLS SYSTEM CHECK .
  15. If voltage reading is at or near zero voltage, regardless of temperature control knob position, go to next step. If voltage reading is not at or near zero voltage, regardless of temperature control knob position, return to step  10.
  16. Disconnect A/C-heater control panel 3-pin harness connector C-3. Using Connector Test Adapter Kit (J 35616-A), connect jumper wires between connector C-3 and A/C-heater control panel terminals. Using a DVOM connected to ground, backprobe A/C-heater control panel 3-pin connector C-3 terminal "B" (Light Blue wire).

    Turn ignition switch to ON position. Turn headlight switch to PARK position. Move temperature control knob on A/C-heater control panel to hot (Red) and cold (Blue) positions. If voltage reading varies smoothly between zero and 12 volts, go to next step. If voltage reading does not vary smoothly between zero and 12 volts, go to step  18.

  17. Repair open or high resistance in Light Blue wire between A/C-heater control panel and air temperature valve actuator. Perform BLOWER CONTROLS SYSTEM CHECK .
  18. Use a DVOM to backprobe between A/C-heater control panel 3-pin connector C-3 terminals "A" (Brown wire) and "C" (Black wire). If battery voltage exists, go to step  23. If battery voltage does not exist, go to next step.
  19. Using a DVOM connected to ground, backprobe A/C-heater control panel 3-pin connector C-3 terminal "A" (Brown wire). If battery voltage is indicated, return to step  11. If battery voltage is not indicated, return to step  7.
  20. Check HVAC 1 fuse No. 21. If fuse is okay, go to next step. If fuse is faulty, go to step  22.
  21. Repair short to ground in Brown wire between instrument panel fuse block and A/C-heater control panel harness connector C3 terminal "A". Perform BLOWER CONTROLS SYSTEM CHECK .
  22. Repair open in Light Blue wire between instrument panel fuse block and ignition switch. After repair, perform BLOWER CONTROLS SYSTEM CHECK .
  23. Disconnect jumper wire from connector C-3 terminal "B" (Light Blue wire). With jumper wire still connected to A/C-heater control panel, use a DVOM to measure voltage between jumper wire and ground. Disconnect air temperature valve actuator connector. Move temperature control knob on A/C-heater control panel to hot (Red) and cold (Blue) positions. If voltage reading varies smoothly between zero and 12 volts, go to next step. If voltage reading does not vary smoothly between zero and 12 volts, go to step  11.
  24. Repair short to ground in Light Blue wire between A/C-heater control panel harness connector C3 terminal "B" and air temperature valve actuator. After repair, perform BLOWER CONTROLS SYSTEM CHECK .
scientia non olet · About LEMON Manuals