Test Description
WARNING: This page does not describe the selected car, but rather 7 other vehicles, including the 2002 GMC Yukon XL, 2002 GMC Yukon, 2002 Chevrolet Tahoe, 2002 Chevrolet Suburban, and 2002 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.
The number(s) below refer to the step number(s) on the diagnostic table.
- 2: This step checks for continuous operation of the auxiliary blower motor.
- 3: This step determines if the malfunction is in the auxiliary HVAC control assembly.
- 4: This step tests for a short to ground in the control side of the system. It is easiest to perform this step by disconnecting the auxiliary blower motor resistor assembly connector C1 and the auxiliary HVAC control assembly. Test each auxiliary blower motor speed control circuit for continuity to a known good ground.
Blower Motor Always On - Auxiliary (W/Sunroof or Heat Only)
| Step | Action | Yes | No |
|---|---|---|---|
| Schematic Reference: HVAC Schematics DEFINITION: The auxiliary blower motor is on while the auxiliary blower motor switch is in the OFF position. |
|||
| 1 | Did you review the auxiliary HVAC operation and perform the necessary inspections? | Go to Step 2 | Go to SYMPTOM TESTS |
| 2 |
|
Go to TESTING FOR INTERMITTENT AND POOR CONNECTIONS | Go to Step 3 |
| 3 |
|
Go to Step 6 | Go to Step 4 |
| 4 | Test each auxiliary blower motor speed control circuit between the auxiliary blower motor resistor assembly and the auxiliary HVAC control assembly for a short to ground. Refer to CIRCUIT TESTING
and WIRING REPAIRS
. Did you find and correct the condition? |
Go to Step 9 | Go to Step 5 |
| 5 | Inspect for poor connections at the harness connector of the auxiliary blower motor resistor assembly. Refer to TESTING FOR INTERMITTENT AND POOR CONNECTIONS
and CONNECTOR REPAIRS
. Did you find and correct the condition? |
Go to Step 9 | Go to Step 8 |
| 6 | Inspect for poor connections at the harness connector of the auxiliary HVAC control assembly. Refer to TESTING FOR INTERMITTENT AND POOR CONNECTIONS
and CONNECTOR REPAIRS
. Did you find and correct the condition? |
Go to Step 9 | Go to Step 7 |
| 7 | Replace the auxiliary HVAC control assembly. Refer to HVAC CONTROL ASSEMBLY - FRONT AUXILIARY (FRONT OVERHEAD CONTROL A/C ONLY)
or HVAC CONTROL ASSEMBLY - FRONT AUXILIARY (FRONT OVERHEAD CONTROL HEAT & A/C)
or HVAC CONTROL ASSEMBLY - REAR AUXILIARY
. Did you complete the replacement? |
Go to Step 9 | - |
| 8 | Replace the auxiliary blower motor resistor assembly. Refer to BLOWER MOTOR RESISTOR - AUXILIARY
. Did you complete the replacement? |
Go to Step 9 | - |
| 9 | Operate the system in order to verify the repair. Did you correct the condition? |
System OK | Go to Step 2 |