Test Description
The number below refers to the step number on the diagnostic table.
Step | Action | Yes | No |
|---|---|---|---|
Schematic Reference: Defogger Schematics Connector End View Reference: Stationary Windows Connector End Views DEFINITION: The rear window defogger is completely inoperative. No part of the rear window is heated. | |||
1 | Did you review the operation of the rear window defogger system and perform the necessary inspections? | Go to Step 2 | |
2 |
Does the indicator illuminate? | Go to Step 3 | Go to Step 6 |
3 |
Does the test lamp illuminate on both rear window defogger grids? | Go to Step 4 | Go to Step 5 |
4 |
Does the test lamp illuminate on both rear window defogger grids? | Go to Testing for Intermittent Conditions and Poor Connections | Go to Step 19 |
5 | Does the test lamp illuminate on one of the rear window defogger grids? | Go to Step 20 | Go to Step 9 |
6 |
Does the test lamp illuminate? | Go to Step 7 | Go to Step 14 |
7 | Connect a test lamp between the ignition voltage circuit, terminal B of the HVAC Control Assembly and a good ground. Does the test lamp illuminate? | Go to Step 8 | Go to Step 21 |
8 | Connect a test lamp between the ignition voltage circuit and the ground circuit, terminal C of the HVAC Control Assembly. Does the test lamp illuminate? | Go to Step 17 | Go to Step 22 |
Command the RR DEFOG relay ON and OFF, by depressing the rear window defogger switch on the HVAC Control Assembly. Does the RR DEFOG relay click when commanded ON and OFF? | Go to Step 12 | Go to Step 10 | |
10 |
Does the test lamp illuminate? | Go to Step 11 | Go to Step 15 |
11 | Connect a test lamp between the supply voltage circuit and the ground circuit of the RR DEFOG relay coil. Does the test lamp illuminate? | Go to Step 18 | Go to Step 24 |
12 |
Does the test lamp illuminate? | Go to Step 13 | Go to Step 16 |
13 |
Does the test lamp illuminate? | Go to Step 18 | Go to Step 20 |
14 | Test the battery positive voltage circuit of the HVAC Control Assembly for an open or short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 28 | Go to Step 23 |
15 | Test the supply voltage circuit of the RR DEFOG relay coil for an open or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 28 | Go to Step 17 |
16 | Test the battery positive voltage circuit of the RR DEFOG relay switched input for an open or short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 28 | Go to Step 25 |
17 | Inspect for a poor connection at the harness connector of the HVAC Control Assembly. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 28 | Go to Step 26 |
18 | Inspect for a poor connection at the RR DEFOG relay. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 28 | Go to Step 27 |
19 | Repair an open or high resistance in the ground circuit of the rear window defogger grid. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 28 | -- |
20 | Repair an open or high resistance in the supply voltage circuit of the rear window defogger grid. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 28 | -- |
21 | Repair an open or high resistance in the ignition voltage circuit of the HVAC Control Assembly. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 28 | -- |
22 | Repair an open or high resistance in the ground circuit of the HVAC Control Assembly. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 28 | -- |
23 | Repair the short to ground in the supply voltage circuit of the RR DEFOG relay coil. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 28 | -- |
24 | Repair an open or high resistance in the ground circuit of the RR DEFOG relay coil. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 28 | -- |
25 | Repair the short to ground in the supply voltage circuit of the rear window defogger grid. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 28 | -- |
26 | Replace the HVAC Control Assembly. Refer to Heater and Air Conditioning Control Replacement in HVAC Systems - Manual. Did you complete the replacement? | Go to Step 28 | -- |
27 | Replace the RR DEFOG relay. Refer to Relay Replacement in Wiring Systems. Did you complete the replacement? | Go to Step 28 | -- |
28 | Operate the system in order to verify the repair. Did you correct the condition? | System OK | Go to Step 2 |
