For 1990-2009 cars

Step | Action | Yes | No
--- | --- | --- | ---
1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | Go to Diagnostic System Check - Vehicle
2 |

1. Start the engine.
2. Depress the rear window defogger switch.
3. Observe the rear window defogger indicator on the switch.

Does the rear window defogger indicator illuminate?

Go to Step 3

Go to Testing for Intermittent Conditions and Poor Connections

3 | Connect a test lamp between the rear window defogger grid and a good ground. Does the test lamp illuminate? | Go to Step 4 | Go to Step 6
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 Defogger Grid Lines Diagnosis | Go to Step 5
5 | Repair an open or high resistance on the ground circuit of the rear window defogger. Refer to Wiring Repairs . Did you complete the repair? | Go to Step 7 | --
6 | Repair an open or high resistance on the supply circuit of the rear window defogger. Refer to Wiring Repairs . Did you complete the repair? | Go to Step 7 | --
7 | Operate the system in order to verify the repair. Did you correct the condition? | System OK | Go to Step 2