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 numbers below refer to the step numbers on the diagnostic table.
- 2: This step tests for auxiliary blower motor operation in any speed setting.
- 8: This step determines if the malfunction is in the control side of the system.
- 9: Test both the auxiliary HVAC control assembly chassis ground circuit and ground loop circuit.
Blower Motor Inoperative - Auxiliary (W/Sunroof or Heat Only)
| Step | Action | Yes | No |
|---|---|---|---|
| Schematic Reference: HVAC Schematics DEFINITION: The auxiliary blower motor is inoperative in all speed positions. |
|||
| 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 4 | Go to Step 6 |
| 4 | Connect a test lamp between the auxiliary blower motor supply circuit and the auxiliary blower motor ground circuit. Does the test lamp illuminate? |
Go to Step 11 | Go to Step 5 |
| 5 | Test the ground circuit of the auxiliary blower motor resistor assembly for an open or high resistance. Refer to CIRCUIT TESTING
and WIRING REPAIRS
. Did you find and correct the condition? |
Go to Step 18 | Go to Step 12 |
| 6 |
|
Go to Step 7 | Go to Step 13 |
| 7 | Probe the auxiliary blower motor resistor assembly battery positive voltage circuit with a test lamp that is connected to a good ground. Does the test lamp illuminate? |
Go to Step 8 | Go to Step 14 |
| 8 |
|
Go to Step 12 | Go to Step 9 |
| 9 | Test the auxiliary HVAC control assembly ground circuits for an open or high resistance. Refer to CIRCUIT TESTING
and WIRING REPAIRS
. Did you find and correct the condition? |
Go to Step 18 | Go to Step 10 |
| 10 | 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 18 | Go to Step 15 |
| 11 | Inspect for poor connections at the harness connector of the auxiliary blower motor. Refer to TESTING FOR INTERMITTENT AND POOR CONNECTIONS
and CONNECTOR REPAIRS
. Did you find and correct the condition? |
Go to Step 18 | Go to Step 16 |
| 12 | Inspect for poor connections at the harness connectors 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 18 | Go to Step 17 |
| 13 | Repair the ignition 3 voltage circuit of the auxiliary blower motor resistor assembly. Refer to WIRING REPAIRS
. Did you complete the repair? |
Go to Step 18 | - |
| 14 | Repair the battery positive voltage circuit of the auxiliary blower motor resistor assembly. Refer to WIRING REPAIRS
. Did you complete the repair? |
Go to Step 18 | - |
| 15 | Replace 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 18 | - |
| 16 | Replace auxiliary blower motor. Refer to BLOWER MOTOR - AUXILIARY
. Did you complete the replacement? |
Go to Step 18 | - |
| 17 | Replace auxiliary blower motor resistor assembly. Refer to BLOWER MOTOR - AUXILIARY
. Did you complete the replacement? |
Go to Step 18 | - |
| 18 | Operate the system in order to verify the repair. Did you correct the condition? |
System OK | Go to Step 2 |