Blower Motor Always On
WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2004 Oldsmobile Bravada, 2004 GMC Envoy XUV, 2004 GMC Envoy XL, 2004 GMC Envoy, and 2004 Chevrolet TrailBlazer. However, it is still accessible from the selected car via links, so may be relevant.
Blower Motor Always On
| Step | Action | Values | Yes | No |
|---|---|---|---|---|
| Schematic Reference: HVAC Schematics Connector End View Reference: HVAC Connector End Views DEFINITION: The blower motor operates with the HVAC controls in the OFF position. |
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| 1 | Did you perform the HVAC Diagnostic System Check? | - | Go to Step 2 | Go to Diagnostic System Check - HVAC Systems - Automatic |
| 2 |
IMPORTANT:
Be sure that the blower motor housing is not shorted to a grounded surface this will cause the blower motor to always be on in high speed.
|
- | Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems | Go to Step 3 |
| 3 | With the scan tool observe the Blower Motor PWM Speed parameter in the Heating and Air Conditioning data list. Does the scan tool indicate that the Blower Motor PWM Speed parameter is near the specified value? |
0% | Go to Step 4 | Go to Step 6 |
| 4 |
|
- | Go to Step 6 | Go to Step 5 |
| 5 | Inspect for poor connections at the harness connector of the blower motor control processor. Refer to Wiring Repairs
and Connector Repairs
in Wiring Systems. Did you find and correct the condition? |
- | Go to Step 9 | Go to Step 7 |
| 6 | Inspect for poor connections at the harness connector of the HVAC control module. Refer to Circuit Testing
and Wiring Repairs
in Wiring Systems. Did you find and correct the condition? |
- | Go to Step 9 | Go to Step 8 |
| 7 | Replace the blower motor control processor. Refer to Blower Motor Control Processor Replacement . Did you complete the replacement? |
- | Go to Step 9 | - |
| 8 |
IMPORTANT:
Perform the recalibration procedure for the HVAC control module. Replace the HVAC control module. Refer to HVAC Control Module Replacement .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 |