I just picked up my car after getting the headlines redone and the rear defroster light is on. I am not excited about tearing out the headliners, so what could have caused this? I guess my fear is that they screwed through the wires.
Location: San Antonio, TX
Posts: 636
My VIN: 4608- sold 4885- current
I just picked up my car after getting the headlines redone and the rear defroster light is on. I am not excited about tearing out the headliners, so what could have caused this? I guess my fear is that they screwed through the wires.
The light wiring just goes to the switch and light via the center console wires. My guess is your defrost switch got bumpped and probably failed. It is turned off?
Dave M vin 03572
http://dm-eng.weebly.com/
Location: San Antonio, TX
Posts: 636
My VIN: 4608- sold 4885- current
Will the back window feel hot if it's on?
Location: San Francisco Bay Area, Calif.
Posts: 2,087
My VIN: 0934
Club(s): (NCDMC) (DCUK)
It might feel warm but the glass may make it hard to tell.
Easy way to determine whether this is power going to the rear defogger grid is to probe across the grid - check the left side and right side defogger grid terminals on the inside of the rear glass with a voltmeter or a 12V test light probe. One probe lead on each terminal. With ignition ON. If the test lamp is on or you see ~12V then the grid is getting power.
Last edited by Rich; 10-04-2014 at 01:13 PM.
March '81, 5-speed, black interior
Location: San Antonio, TX
Posts: 636
My VIN: 4608- sold 4885- current
Switch died. Replaced it and it's all good
Posts: 4,808
My VIN: 3937
I saw something like this happen on my car, Alex. The rear defrost got stuck on because the switch got physically stuck in place while on.
The centre console where the five holes are for the window, dummy and defrost switches can get bent out of shape a little bit over time. My defrost switch got pushed down too far and then when you pushed it with your finger (or elbow by accident) the plastic edge of the switch itself would rub on the vinyl edge of the console/armrest area and not let it release back to the off position.
It doesn't need to move by much to see this happen. That space is pretty small and the switch being just a little out of place is enough to get one or more sides of it to rub against something. Keep that in mind the next time you see the defrost light stay on as it could be another possibility.
Location: San Antonio, TX
Posts: 636
My VIN: 4608- sold 4885- current
Location: Northern NJ
Posts: 8,583
My VIN: 10757 1st place Concourse 1998
Location: Taylors SC
Posts: 5,326
My VIN: (former)05429
Club(s): (DMWC) (DCUK)
Grind or file off the bottom edges of the switches slightly. This isn't a universal problem with the switches, but some consoles are more deformed than others.
Dave S
DMC Midwest - retired but helping
Greenville SC