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Test C: Blower Motor Inoperative

WARNING: This page is about a different car, the 2002 Oldsmobile Intrigue. 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: The blower motor is inoperative in all speed positions.
  1. If diagnostic system check was not performed, go to DIAGNOSTIC SYSTEM CHECK  under SELF-DIAGNOSTIC SYSTEM. If diagnostic system check was performed, go to next step.
  2. Turn ignition on. Place blower switch in each speed position. If blower motor operates in any speed position, go to BLOWER MOTOR MALFUNCTION . If blower motor does not operate in any speed, go to next step.
  3. Place blower switch in maximum speed position. Using scan tool, observe DESIRED BLOWER MTR SPEED parameter in heating and air conditioning data list. If scan tool indicates DESIRED BLOWER MTR SPEED parameter of 111 counts, go to next step. If scan tool does not indicate DESIRED BLOWER MTR SPEED parameter of 111 counts, go to step  12.
  4. Turn ignition off. Disconnect blower motor connector. Turn ignition on. Connect test light between blower motor supply voltage circuit and blower motor control circuit. Place blower switch in minimum speed position. If test light comes on, go to step  10. If test light does not come on, go to next step.
  5. Check battery positive voltage circuit of the blower motor control processor for open, high resistance or short to ground. Repair wiring as necessary. If wiring is okay, go to next step.
  6. Check ground circuit of blower motor control processor for an open circuit or high resistance. Repair wiring as necessary. If wiring is okay, go to next step.
  7. Ensure blower motor control processor and HVAC control module are connected. Backprobe and measure voltage between blower speed control circuit at HVAC control module and ground. Using scan tool, command blower motor OFF and ON. If voltage is near 5.0 volts (OFF) and one volt (ON), go to step  11. If voltage is not near 5.0 volts (OFF) and one volt (ON), go to next step.
  8. Turn ignition off. Disconnect HVAC control module. Turn ignition on. Measure voltage between blower speed control circuit of HVAC control module and ground. If voltage is about 5 volts, go to next step. If voltage is not about 5 volts, go to step  12.
  9. Check blower speed control circuit of HVAC control module for an open, short to ground or short to voltage. Repair wiring as necessary. If wiring is okay, go to step  11.
  10. Check for poor connection at harness connector of blower motor. Repair connector as necessary. If connector is okay, go to step  13.
  11. Check for poor connection at harness connector of blower motor control processor. Repair connector as necessary. If connector is okay, go to step  14.
  12. Check for poor connection at harness connector of HVAC control module. Repair connector as necessary. If connector is okay, go to step  15.
  13. Replace blower motor. See BLOWER MOTOR  under REMOVAL & INSTALLATION. After repairs are complete, go to step  16.
  14. Replace blower motor control processor. See BLOWER MOTOR CONTROL MODULE PROCESSOR  under REMOVAL & INSTALLATION. After repairs are complete, go to step  16.
  15. Replace HVAC control module. See HVAC CONTROL MODULE  under REMOVAL & INSTALLATION. After repairs are complete, go to step  16.
  16. 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.
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