Symptom:
*REAR WINDOW DEFOGGER SWITCH INDICATOR INOPERATIVE
POSSIBLE CAUSES
FUSED REAR WINDOW DEFOGGER RELAY OUTPUT CKT SHORTED TO GROUND
JUNCTION BLOCK FUSE #11
FUSED REAR WINDOW DEFOGGER RELAY OUTPUT CKT OPEN
TEMPERATURE CONTROL HEAD (AZC OR MANUAL)
TEST
ACTION
APPLICABILITY
1
Inspect Junction Block fuse #11.
Is Junction Block fuse #11 open?
All
Yes
→
Go To
2
No
→
Go To
3
2
Turn the ignition off.
Disconnect the Temperature Control Head C1 connector.
Measure the resistance of the Fused Rear Window Defog Relay Output circuit to
ground (from the output side of fuse #11)
Is the resistance below 5.0 ohms?
All
Yes
→
Repair the Fused Rear Window Defogger Relay Output circuit for
a short to ground.
Perform BODY VERIFICATION TEST - VER 1.
No
→
Replace the Junction Block fuse #11.
Perform BODY VERIFICATION TEST - VER 1.
3
Turn the ignition off.
Disconnect the Temperature Control Head C1 connector.
Remove the Rear Window Defogger Relay.
NOTE: Check connectors - Clean/repair as necessary.
Ensure that Junction Block fuse #11 is installed.
Measure the resistance of the Fused rear Window Defogger Relay Output circuit from
the relay output terminal to the Temperature Control Head C1 connector.
Is the resistance below 5.0 ohms?
All
Yes
→
Replace the Temperature Control Head (AZC or manual).
Perform BODY VERIFICATION TEST - VER 1.
No
→
Repair the open Fused Rear Window Defogger Relay Output
circuit.
Perform BODY VERIFICATION TEST - VER 1.
231
ELECTRICALLY HEATED SYSTEMS