Rear Window Defogger Inoperative (SUV)
WARNING: This page is about a different car, the 2007 Hummer H2. However, it is still accessible from the selected car via links, so may be relevant.
Rear Window Defogger Inoperative (SUV)
| Step | Action | Yes | No |
|---|---|---|---|
| Schematic Reference: Defogger Schematics Connector End View Reference: Window Systems Connector End Views |
|||
| 1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | Go to Diagnostic System Check - Vehicle |
| 2 |
|
Go to Step 3 | Go to Step 8 |
| 3 | Connect a test lamp between the left side of the rear window defogger grid and a good ground. Does the test lamp illuminate? |
Go to Step 4 | Go to Step 5 |
| 4 | Connect a test lamp between the left side of the rear window defogger grid and the right side of the rear window defogger grid. Does the test lamp illuminate? |
Go to Testing for Intermittent Conditions and Poor Connections | Go to Step 10 |
| 5 |
|
Go to Step 6 | Go to Step 7 |
| 6 |
|
Go to Step 9 | Go to Step 12 |
| 7 | Test the battery positive voltage circuit of the DEFOG relay switched input for an open or high resistance. Refer to Circuit Testing
and Wiring Repairs
. Did you find and correct the condition? |
Go to Step 15 | Go to Step 11 |
| 8 | Inspect for poor connection at the harness connector of the HVAC Control Module. Refer to Testing for Intermittent Conditions and Poor Connections
and Connector Repairs
. Did you find and correct the condition? |
Go to Step 15 | Go to Step 13 |
| 9 | Inspect for poor connection at the DEFOG relay. Refer to Testing for Intermittent Conditions and Poor Connections
and Connector Repairs
. Did you find and correct the condition? |
Go to Step 15 | Go to Step 14 |
| 10 | Repair an open or high resistance in the ground circuit of the rear window defogger. Refer to Wiring Repairs
. Did you complete the repair? |
Go to Step 15 | - |
| 11 | Repair a short to ground in the supply voltage circuit of the rear window defogger. Refer to Wiring Repairs
. Did you complete the repair? |
Go to Step 15 | - |
| 12 | Repair an open or high resistance in the supply circuit of the rear window defogger. Refer to Wiring Repairs
. Did you complete the repair? |
Go to Step 15 | - |
| 13 | Replace the HVAC control module. Refer to Control Module References
for replacement, setup, and programming. Did you complete the replacement? |
Go to Step 15 | - |
| 14 | Replace the DEFOG relay. Refer to Relay Replacement (Attached to Wire Harness)
or Relay Replacement (Within an Electrical Center)
. Did you complete the replacement? |
Go to Step 15 | - |
| 15 | Operate the system in order to verify the repair. Did you correct the condition? |
System OK | Go to Step 2 |