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I don't think both switches would go bad at the same time. Wilcox site is good but they tell you to test the relay but they don't tell you where it is located.
I I was working on the driver side door when they stopped working. Are the two windows connected somehow?
Here's the best image I've been able to find to depict this stuff. The relay is depicted in Figure C. I'm currently fighting the same issue on my '77. I'm thinking it's a grounding issue for me.
Went out this morning and both windows are working! They are real slow but they're working.
what book did that chart come from? I need a good reference book that shows step by step instructions. Like how to remove the gauges, dash wireing, ect. Can you recommend one?
Went out this morning and both windows are working! They are real slow but they're working.
what book did that chart come from? I need a good reference book that shows step by step instructions. Like how to remove the gauges, dash wiring, ect. Can you recommend one?
I believe it came from the 1977 Electrical Troubleshooting Manual. I dont own one, someone else posted it in a separate thread. But it looks worthwhile.
Went out this morning and both windows are working! They are real slow but they're working.
First, make sure that your battery is fully charged.
According to my shop manual there is a 35 amp circuit breaker that powers the circuit. That goes through a relay triggered by the ignition circuit.
Circuit breakers have a definite life span, and they are cheap and readily available, so I'd start with replacing that. Might have developed high internal resistance.
I have the same problem with my 75, I replaced the switch and the windows worked a few times and stopped , after that I replaced the c/breaker and they worked again but would only work on/off at times so these repairs did not fix the problem. After looking at the above wire chart I see that there's a relay that may be the problem. Thanks for posting that chart I made a copy of it.
Last edited by gmcman52; Apr 30, 2020 at 11:01 AM.
The other day my drivers side window would no go up, so last night I spent several hours last night tracing the problem to the switch, then removing it, repairing, testing then replacing only to have it fail immediately.
The contacts have to handle lots of amps and were a mess. I filed them down like we used to do back in the day with ignition points, maybe get a few more years out of it. I think that the switch failed because the polymer board separated from the pot metal chassis. It is held in by cinching the edges of the chassis that were just un-cinched to disassemble. So I ordered two new switches late last night.
This morning I found a you-tube video where a guy had the exact problem, board separation, on new switches, so he epoxied them in. I'll do that with my new ones.
Have a cold spell?
This winter, my windows got real sluggish. The fix was to clean out the old grease that had solidified inside the door and spray grease all the runners and wheels. Amazing difference.
