RAM 2500 Van V8-5.2L Prop VIN 2 (2000)
Rear Window Defogger: Testing and Inspection
Window Defogger System Control Test
WARNING: ON VEHICLES EQUIPPED WITH AIRBAGS, REFER TO AIRBAGS AND SEAT BELTS/AIRBAGS BEFORE
ATTEMPTING ANY STEERING WHEEL, STEERING COLUMN, OR INSTRUMENT PANEL COMPONENT DIAGNOSIS OR SERVICE.
FAILURE TO TAKE THE PROPER PRECAUTIONS COULD RESULT IN ACCIDENTAL AIRBAG DEPLOYMENT AND POSSIBLE
PERSONAL INJURY.
1. Check the fuses in the fuseblock module and the Power Distribution Center (PDC). If OK, go to Step 2. If not OK, repair the shorted circuit or
component as required and replace the faulty fuse.
2. Check for battery voltage at the fused B(+) fuse in the PDC. If OK, go to Step 3. If not OK, repair the open circuit to the battery as required.
3. Turn the ignition switch to the ON position. Check for battery voltage at the fused ignition switch output (run) fuse in the fuseblock module. If
OK, go to Step 4. If not OK, repair the open fused ignition switch output (run) circuit to the ignition switch as required.
4. Disconnect and isolate the battery negative cable. Remove the heater and air conditioner control from the instrument panel. Unplug the 4-way rear
window defogger switch wire harness connector from the control. Check for continuity between the ground circuit cavity of the rear window
defogger switch wire harness connector and a good ground. There should be continuity. If OK, go to Step 5. If not OK, repair the open circuit to
ground as required.
5. Connect the battery negative cable. Check for battery voltage at the fused B(+) circuit cavity of the rear window defogger switch wire harness
connector. If OK, go to Step 6. If not OK, repair the open circuit to the fuse in the PDC as required.
6. Turn the ignition switch to the ON position. Check for battery voltage at the fused ignition switch output (run) circuit cavity of the rear window
defogger switch wire harness connector. If OK, go to Step 7. If not OK, repair the open fused ignition switch output (run) circuit to the fuse in the
fuseblock module as required.
7. Turn the ignition switch to the OFF position. Disconnect and isolate the battery negative cable. Reconnect the 4-way rear window defogger switch
wire harness connector to the heater and air conditioner control. Connect the battery negative cable. Turn the ignition switch to the ON position.
Depress and release the rear window defogger switch. The amber rear window defogger indicator lamp above the switch button should light. If
OK, go to Step 8. If not OK, replace the faulty heater and air conditioner control assembly.
8. Back probe the rear defogger relay output circuit cavity of the rear window defogger switch wire harness connector and check for battery voltage.
If OK, see Rear Glass Heating Grid. If not OK, replace the faulty heater and air conditioner control assembly.
