Test Description
The number below refers to the step number on the diagnostic table.
- 5: Listen for an audible click when the RR DEFOG relay operates. Command both the ON and OFF states of the RR DEFOG relay. Repeat the commands as necessary.
Defogger Inoperative - Rear Window (w/o Cargo Doors)
| Step | Action | Yes | No |
|---|---|---|---|
| Schematic Reference: Defogger Schematics | |||
| 1 | Did you review the operation of the rear window defogger system and perform the necessary inspections? | Go to Step 2 | Go to Symptoms - Stationary Windows |
| 2 |
|
Go to Step 3 | Go to Step 10 |
| 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 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 AND POOR CONNECTIONS | Go to Step 14 |
| 5 | Command the RR DEFOG relay ON and OFF, by depressing the rear window defogger switch on the HVAC Control Module. Do you hear a click when you command the RR DEFOG relay ON and OFF? |
Go to Step 8 | Go to Step 6 |
| 6 |
|
Go to Step 7 | Go to Step 15 |
| 7 |
|
Go to Step 12 | Go to Step 10 |
| 8 |
|
Go to Step 9 | Go to Step 11 |
| 9 |
|
Go to Step 12 | Go to Step 17 |
| 10 | Test the control circuit of the RR DEFOG relay for an open or short to battery positive voltage. Refer to CIRCUIT TESTING
and WIRING REPAIRS
. Did you find and correct the condition? |
Go to Step 20 | Go to Step 13 |
| 11 | Test the battery positive circuit of the RR DEFOG relay switch for an open or high resistance. Refer to CIRCUIT TESTING
and WIRING REPAIRS
. Did you find and correct the condition? |
Go to Step 20 | Go to Step 16 |
| 12 | Inspect for a poor connection at the RR DEFOG relay. Refer to TESTING FOR INTERMITTENT AND POOR CONNECTIONS
and CONNECTOR REPAIRS
. Did you find and correct the condition? |
Go to Step 20 | Go to Step 18 |
| 13 | Inspect for a poor connection at the harness connector of the HVAC Control Module. Refer to TESTING FOR INTERMITTENT AND POOR CONNECTIONS
and CONNECTOR REPAIRS
. Did you find and correct the condition? |
Go to Step 20 | Go to Step 19 |
| 14 | Repair an open or high resistance in the ground circuit of the rear window defogger grid. Refer to WIRING REPAIRS
. Did you complete the repair? |
Go to Step 20 | - |
| 15 | Repair an open or high resistance in the ignition 1 voltage circuit of the RR DEFOG relay coil. Refer to WIRING REPAIRS
. Did you complete the repair? |
Go to Step 20 | - |
| 16 | Repair the 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 20 | - |
| 17 | Repair an open or high resistance in the supply voltage circuit of the rear window defogger. Refer to WIRING REPAIRS
. Did you complete the repair? |
Go to Step 20 | - |
| 18 | Replace the RR DEFOG relay. Did you complete the replacement? |
Go to Step 20 | - |
| 19 | Replace the HVAC Control Module. Refer to HVAC CONTROL ASSEMBLY
for manual HVAC system or HVAC CONTROL MODULE REPLACEMENT
for automatic HVAC system. Did you complete the replacement? |
Go to Step 20 | - |
| 20 | Operate the system in order to verify the repair. Did you correct the condition? |
System OK | Go to Step 2 |