LEMON Manuals: Even more car manuals for everyone
Home >> Chevrolet >> 2002 >> Blazer 4D Utility, 4WD, Part Time >> Repair and Diagnosis >> Heating, Ventilation & A/C (HVAC) >> HVAC Control Systems >> Heater Systems >> Symptom Tests >> Test "C": Blower Motor Inoperative

Test "C": Blower Motor Inoperative

NOTE: For circuit reference, see CONNECTOR IDENTIFICATION  and/or WIRING DIAGRAMS  .
NOTE: Definition: The blower motor is inoperative in all speed positions.
  1. Did you perform the HVAC Diagnostic System Check? If so, go to next step. If not, see DIAGNOSTIC SYSTEM CHECK .
  2. Turn the ignition on, with the engine off. Place the mode switch in the vent position. Place the blower motor switch in each speed position. Does the blower motor operate in any of the speed positions? If so, go to BLOWER MOTOR MALFUNCTION . If not, go to next step.
  3. Turn the ignition off. Disconnect the blower motor. Turn the ignition on, with the engine off. Connect a test light between the blower motor supply voltage circuit and ground. Place the blower motor switch in the minimum speed position. Does the test light illuminate? If so, go to next step. If not, go to step  5.
  4. Test the blower motor ground circuit for an open or high resistance. See WIRING DIAGRAMS . Did you find and correct the condition? If so, go to step  16. If not, go to step  10.
  5. Turn the ignition off. Disconnect the blower motor resistor. Turn the ignition on, with the engine off. Place the blower motor switch in the minimum speed position. Connect a test light from the blower motor resistor terminal "B" (Brown wire) and ground. Does the test light illuminate? If so, go to step  8. If not, go to next step.
  6. Test the blower motor resistor circuit for an open or high resistance. See WIRING DIAGRAMS . Did you find and correct the condition? If so, go to step  16. If not, go to next step.
  7. Turn the ignition off. Disconnect the HVAC control assembly connector "C2". Connect a test light between the HVAC control assembly, harness connector terminal "C" (Brown wire) and ground. Turn the ignition on, with the engine off. Does the test light illuminate? If so, go to step  11. If not, go to step  12.
  8. Test the blower motor supply circuit for an open, high resistance or short to ground. SeeWIRING DIAGRAMS  . Did you find and correct the condition? If so, go to step  16. If not, go to next step.
  9. Inspect the blower motor relay for poor connections. See SYMPTOM DIAGNOSIS  under TROUBLE SHOOTING. Did you find and correct the condition? If so, go to step  16. If not, go to step  13.
  10. Inspect the blower motor for poor connections. See SYMPTOM DIAGNOSIS  under TROUBLE SHOOTING. Did you find and correct the condition? If so, go to step  16. If not, go to step  14.
  11. Inspect the HVAC control assembly for poor connections. Did you find and correct the condition? If so, go to step  16. If not, go to step  15.
  12. Repair the HVAC control assembly ignition circuit. See WIRING DIAGRAMS . After repairs are completed, go to step  16.
  13. Replace the blower motor relay. See BLOWER MOTOR RELAY  under REMOVAL & INSTALLATION. After repairs are completed, go to step  16.
  14. Replace the blower motor. See BLOWER MOTOR & FAN  under REMOVAL & INSTALLATION. After repairs are completed, go to step  16.
  15. Replace the HVAC control assembly. See HVAC CONTROL ASSEMBLY  under REMOVAL & INSTALLATION. After repairs are completed, 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  3.
scientia non olet · About LEMON Manuals