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Test D: Blower Motor Always On

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: The blower motor is on while the mode switch in the OFF position.
  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  .
  2. Turn ignition on. Place mode switch in OFF position. If blower motor is off, problem is intermittent. Check wiring and connectors for damage and poor connections. If blower motor is on, go to next step.
  3. Turn ignition off. Disconnect harness connector from blower motor resistor. See Figure. Turn ignition on. Using a test light connected to ground, probe each harness connector terminal. If test light illuminates on any terminal, go to next step. If test light does not illuminate on any terminal, go to step  5.
  4. Check voltage supply circuit (Brown wire and White wire) to blower switch, and suspect blower control circuit for a short to voltage. See WIRING DIAGRAMS . If a short to voltage was found, repair as necessary and go to step  9. If a short to voltage was not found, go to step  6.
  5. Check harness connector at blower motor resistor for poor connections. If a poor connection condition was found, repair as necessary and go to step  9. If a poor connection was not found, go to step  7.
  6. Check main HVAC control assembly harness connector for a poor connection condition. If a poor connection was found, repair as necessary and go to step  9. If a poor connection was not found, go to step  8.
  7. Replace blower motor resistor. See Figure. After repairs are complete, go to step  9.
  8. Replace main HVAC control assembly. See MAIN HVAC CONTROL ASSEMBLY  under REMOVAL & INSTALLATION. If replacement is complete, go to next step.
  9. Operate system to verify repair. If the condition was corrected, system is okay. If the condition was not corrected, return to step  2.
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