Rear Window Defogger Inoperative Does Not Turn Off - Always On
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 |
Is the test light on? | -- | Go to Step 4 | Go to Step 2 |
2 | Using a test light, probe between the rear window defogger relay connector terminal A2 and ground. Is the test light on? | -- | Go to Step 7 | Go to Step 3 |
3 | Replace the rear window defogger relay. Is the repair complete? | -- | System OK | -- |
4 | Check for a short to ground in circuit 193 (WHT). Is there a short to ground in circuit 193 (WHT)? | -- | Go to Step 5 | Go to Step 6 |
5 | Repair the short to ground in circuit 193 (WHT). Is the repair complete? | -- | System OK | -- |
6 | Replace the heater-A/C control. For manual systems refer to Control Assembly Replacement and for automatic systems refer to Control Assembly Replacement in Instrument Panel Gauges and Console. Is the repair complete? | -- | System OK | -- |
7 |
Is the test light on? | -- | Go to Step 8 | Go to Step 9 |
8 | Repair short to B+ in circuit 293 (PPL). Is the repair complete? | -- | System OK | -- |
9 | Repair short to B+ in circuit 267. Is the repair complete? | -- | System OK | -- |
Rear Window Defogger Inoperative Including Rearview Mirrors
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 | Was the defogger system check performed? | -- | Go to Step 2 | Go to Defogger System Check |
2 |
Are the REAR DEFOG circuit breaker and the HVAC fuse OK? | -- | Go to Step 3 | Go to Step 5 |
3 | Turn on the rear defogger switch. Does the rear defogger indicator lamp turn on? | -- | Go to Step 7 | Go to Step 4 |
4 | Replace the heater-A/C control. For manual systems refer to Control Assembly Replacement and for automatic systems refer to Control Assembly Replacement in Instrument Panel Gauges and Console. Is the repair complete? | -- | System OK | -- |
5 | Is the HVAC fuse open? | -- | Go to Step 21 | Go to Step 6 |
6 | Is the REAR DEFOG circuit breaker open? | -- | Go to Step 14 | Go to Step 7 |
7 | Use a test light to backprobe between the rear window defogger connector terminal C1 and ground. Is the test light on? | -- | Go to Step 8 | Go to Step 13 |
8 |
Is the test light on? | -- | Go to Step 9 | Go to Step 15 |
9 | Use a test light connected to ground to check for power at the HEATED MIRROR fuse. Is there power at the HEATED MIRROR fuse? | -- | Go to Step 10 | Go to Step 18 |
10 |
Is the test light on? | -- | Go to Step 11 | Go to Step 19 |
11 | Use a test light to backprobe between B+ and the outside rearview mirror connector terminal E . Is the test light on? | -- | Go to Step 12 | Go to Step 20 |
12 | Replace the inoperative outside rearview mirror. Refer to Outside Rearview Mirror Glass Replacement in Doors. Is the repair complete? | -- | System OK | -- |
13 | Repair poor connection or open in circuit 1040 (ORN). Is the repair complete? | -- | System OK | -- |
14 | Repair short to ground in circuit 1040 (ORN) and/or circuit 293 (PPL). Is the repair complete? | -- | System OK | -- |
15 |
When cycling the rear defogger switch, does the DMM display a change of resistance between ∞ (OL) and less than 2ohms? | -- | Go to Step 17 | Go to Step 16 |
16 | Replace the rear window defogger relay. Is the repair complete? | -- | System OK | -- |
17 | Check for poor connection or open at the rear window defogger relay terminals A2 and/or C1 and repair as needed. Is the repair complete? | -- | System OK | -- |
18 | Repair poor connection or open in circuit 293 (PPL) between S268 and the HEATED MIRROR fuse block terminal A5. Is the repair complete? | -- | System OK | -- |
19 | Repair poor connection or open in circuit 267 (ORN) between C200 terminal G2 and the inoperative outside rearview mirror. Is the repair complete? | -- | System OK | -- |
20 | Repair poor connection or open in circuit 750 (BLK). Is the repair complete? | -- | System OK | -- |
21 | Repair short to ground in circuit 41 (BRN). Is the repair complete? | -- | System OK | -- |
Rear Window Defogger Inoperative Rearview Mirrors Operate
Step | Action | Value(s) | Yes | No | ||||
|---|---|---|---|---|---|---|---|---|
1 | Was the defogger system check performed? | -- | Go to Step 2 | Go to Defogger System Check | ||||
2 |
Is the defogger indicator lamp on? | -- | Go to Step 3 | Go to Step 13 | ||||
3 | Using a test light, backprobe between the rear window defogger relay connector terminal C1 and ground. Is the test light on? | -- | Go to Step 8 | Go to Step 10 | ||||
4 |
Is the test light on? | -- | Go to Step 5 | Go to Step 7 | ||||
5 | Repair the rear defogger grid. Refer to Grid Line Repair . Is the repair complete? | -- | System OK | -- | ||||
6 |
Is the test light on? | -- | Go to Step 4 | Go to Step 9 | ||||
7 | Repair poor connection or open in circuit 450 between the rear defogger grid and G401. Is the repair complete? | -- | System OK | -- | ||||
8 | Using a test light, backprobe between the rear window defogger relay connector terminal A2 and ground. Is the test light on? | -- | Go to Step 6 | Go to Step 16 | ||||
9 | Repair poor connection or open in circuit 293 between the rear window defogger relay connector terminal A2 and the rear defogger grid. Is the repair complete? | -- | System OK | -- | ||||
10 | Check the REAR DEFOG circuit breaker. Is the REAR DEFOG circuit breaker open? | -- | Go to Step 11 | Go to Step 12 | ||||
11 | Repair short to ground in circuit 293 (PPL) or circuit 1040 (ORN). Is the repair complete? | -- | System OK | -- | ||||
12 | Repair poor connection or open in circuit 1040 (ORN). Is the repair complete? | -- | System OK | -- | ||||
13 | Using a test light, backprobe between the rear window defogger relay connector terminal C2 and ground. Is the test light on? | -- | Go to Step 14 | Go to Step 17 | ||||
14 |
When cycling the rear defogger switch, does the DMM measure a voltage between B+ and 0.5V (or less)? | -- | Go to Step 15 | Go to Step 20 | ||||
15 | Replace the heater-A/C control. For manual systems refer to Control Assembly Replacement and for automatic systems refer to Control Assembly Replacement in Instrument Panel Gauges and Console. Is the repair complete? | -- | System OK | -- | ||||
16 | Replace the rear window defogger relay. Is the repair complete? | -- | System OK | -- | ||||
17 | Check the HVAC fuse. Is the HVAC fuse open? | -- | Go to Step 18 | Go to Step 19 | ||||
18 | Repair short to ground in circuit 41 (BRN). Is the repair complete? | -- | System OK | -- | ||||
19 | Repair poor connection or open in circuit 41 (BRN). Is the repair complete? | -- | System OK | -- | ||||
20 | Does the DMM remain reading B+ (10-14V)? | -- | Go to Step 21 | Go to Step 25 | ||||
21 | Check for a poor connection or open in circuit 193 (WHT). Is there a poor connection or open in circuit 193 (WHT)? | -- | Go to Step 22 | Go to Step 23 | ||||
22 | Repair poor connection or open in circuit 193 (WHT). Is the repair complete? | -- | System OK | -- | ||||
23 | Using a test light connected to B+, backprobe the heater-A/C control:
is the test light on? | -- | Go to Step 15 | Go to Step 24 | ||||
24 | Repair poor connection or open in circuit 1450 (BLK). Is the repair complete? | -- | System OK | -- | ||||
25 | Does the DMM remain at 0.5V, or less? | -- | Go to Step 26 | Go to Step 23 | ||||
26 | Check for a short to ground in circuit 193 (WHT). Is there a short to ground in circuit 193? | -- | Go to Step 27 | Go to Step 15 | ||||
27 | Repair short to ground in circuit 193 (WHT). Is the repair complete? | -- | System OK | -- |
