LEMON Manuals: Even more car manuals for everyone
Home >> Chevrolet >> 2002 >> Blazer 4D Utility, 4WD, Part Time >> Repair and Diagnosis >> External Pages >> Different car >> Section 25 (HVAC Systems - Automatic) >> Symptom Tests >> Test F: Blower Motor Malfunction

Test F: Blower Motor Malfunction

WARNING: This page is about a different car, the 2002 Oldsmobile Aurora. However, it is still accessible from the selected car via links, so may be relevant.
  1. Perform diagnostic system check. See DIAGNOSTIC SYSTEM CHECK  under SELF-DIAGNOSTIC SYSTEM. After performing system check, go to next step.
  2. Turn ignition ON, engine OFF. Place blower switch in each speed position. If blower operates in all speed positions, test for intermittent loose wires and/or poor connections. See INTERMITTENTS  under TROUBLE SHOOTING. If blower motor does not operate in all speed positions, go to next step.
  3. Connect scan tool. Observe COMMAND BLOWER parameter in the instrument panel module data list. Move Blower Motor switch from lowest to highest speeds. If scan tool indicates COMMAND BLOWER parameter increases from 10-100 percent, go to next step. If scan tool indicates command blower does not reach 10-199 percent, go to step  10.
  4. Turn ignition OFF. Disconnect Blower Motor harness connector. Turn ignition on, engine off. Connect a DVOM between terminals "A" (Black wire) and "B" (Purple wire) of blower motor harness connector. Adjust Blower Motor switch from lowest to highest speed positions. If DVOM shows voltage and voltage increases toward highest speed position, go to step  8. If DVOM does not shows voltage and voltage increases toward highest speed position, go to next step.
  5. Check Orange wire between HVAC BLO fuse (30-amp) and terminal "B" of Blower Motor Control Processor harness connector for open or high resistance. If open or high resistance is found, repair as necessary. Go to step  16. If open or high resistance is not found, go to next step.
  6. Connect Blower Motor Control Processor and Instrument Panel Module (IPM) harness connectors. Measure voltage between ground and terminal D11 (Gray/Black wire) of IPM harness connector C1. See Figure. Move Blower Motor switch from lowest to highest speed position. If voltage at lowest position is around 4.75 volts and 1.5 volts at highest position, go to step  9. If voltage is not 4.75 volts at lowest position and 1.5 volts at highest position, go to next step.
  7. Turn ignition OFF. Disconnect IPM. Turn ignition ON, engine off. Using a DVOM, measure voltage at IPM connector C1 terminal D11 (Gray/Black wire). If measured voltage is near 5.0 volts, go to step  11. If measured voltage is not near 5.0 volts, go to step  9.
  8. Check for loose wires and/or poor connections at Blower Motor harness connector. If poor connection is found, repair as necessary. Go to step  16. If poor connection is not found, go to step  12.
  9. Check for loose wires and/or poor connections at Blower Motor Control Processor. If poor connection is found, repair as necessary. Go to step  16. If poor connection is not found, go to step  13.
  10. Check for loose wires and/or poor connections at HVAC Module harness connector. If poor connection is found, repair as necessary. Go to step  16. If poor connection is not found, go to step  14.
  11. Check for loose wires and/or poor connections at IPM harness connector. If poor connection is found, repair as necessary. Go to step  16. If poor connection is not found, go to step  15.
  12. Replace Blower Motor. See BLOWER MOTOR  under REMOVAL & INSTALLATION. Go to step  16.
  13. Replace Blower Motor Control Processor. See BLOWER MOTOR CONTROL PROCESSOR  under REMOVAL & INSTALLATION. Go to step  16.
  14. Replace HVAC Control Module. See HVAC CONTROL MODULE  under REMOVAL & INSTALLATION. Go to step  16.
  15. Replace IPM. See INSTRUMENT PANEL MODULE (IPM)  under REMOVAL & INSTALLATION. Go to step  16.
  16. Operate system to verify repair. If condition is corrected, system is okay. If condition is not corrected, go to step  2.
scientia non olet · About LEMON Manuals