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I own a 1972 coupe (purchased in 2018). The electric windows were working fine for 3 years, then one day they stopped working, The window motors and regulators were replaced in 2018 by previous owner. I'm not very good with electrical problems (really wouldn't know where to start).
Can anyone offer some insight or help??
When trouble shooting, if neither window operates, look for faults in circuitry common to both window motors and the 30amp PWR ACCY circuit breaker in the fuse block. 1979 shop manual
SInce you say that you're 'not very good with electrical problems' (neither am I, by the way), please excuse if this is too basic.
Do you have a test light, similar to this:
If you do, test the power window circuit breaker. Here it is on our (and your) 1972. With the clamp end of the test light grounded (I attached it to the adjusting bolt at the top of the alternator), a working unit will light up the lamp from both terminals, shown below. If one terminal lets the lamp remain dark, the circuit breaker is bad.
Let us know what you find.
Last edited by Catfish4818; Jul 14, 2021 at 01:34 PM.
I should have added, if the terminal with the red wire lets the lamp stay dark, you may have a problem at the wire's other end. It connects to the horn relay, and gets power from there. Check for loose or corroded connections where the wire is attached to the horn relay.
Here's your horn relay:
Last edited by Catfish4818; Jul 14, 2021 at 01:32 PM.
Reason: added photos
Catfish4818 - I do have a light tester similar to the one you have. To update you on this problem, I did not know where the 30 amp CB was located. I thought it was behind the driver side kick shield. I removed the shield and could not find anything that looked like a CB. I then started to use my light tester on the fuses in the fuse box. The first fuse I touched was the 10 amp (lower right side). It shorted out. I replaced the 10 amp fuse and the pwr windows are working. Don't have a clue as to why. I replaced the kick shield and button up the car.
Thx for trying to help me out.
Catfish4818 - I have an amendment to my last post of 7-14-21. I started the car today and the electric windows are NOT working. I checked the CB with the light tester. The terminal closest to the engine did not light up the tester light. Then I checked the terminal closest to firewall and got a spark but the tester light did not light. Does this mean I need to replace the 30 amp CB?
Looking at the horn relay, it shows quite a bit of rust on the terminal but up until now everything has been working on the car.
Hmm...that confuses me. For the firewall-side terminal of the CB to spark the test lamp, it means the CB must have power passing through it, which means the engine-side terminal must have juice, but you report no juice there. The engine-side terminal gets it's power through the red wire attached to the stud on the horn relay. Just for grins, does the test light light up when you touch the HR stud? (it should)
As a test, to make sure that the red wire is OK, do you have a length of wire you can use to jump from the HR stud to the CB engine-side terminal, and see if that makes a difference? That's all that the red wire is - a jump that snakes down the wheelhouse and under the master cylinder and/or power booster, coming up to connect to the CB.
I can't really answer your question about is the CB bad and replacing it, because so far whether or not it's getting power is in question. That engine-side term SHOULD light up regardless.
Catfish4818 - I just checked the horn relay with the light tester. I got not light but there was some smoke coming of the tester wire so I quickly disconnected it. Do you think we found the problem?
Catfish4818 - I can take a picture of it with my phone. However, I'm not computer knowledgeable enough to know how to send the photo to you. My better half says, if we had a phone number she can send it to you, if you are agreeable to doing it that way. If not, I will need to find another family member who can help me.
Catfish4818 - I can take a picture of it with my phone. However, I'm not computer knowledgeable enough to know how to send the photo to you. My better half says, if we had a phone number she can send it to you, if you are agreeable to doing it that way. If not, I will need to find another family member who can help me.
OK, well, the stud on the HR should make it produce a steady light. If not, somethings wrong there.
And if not, the next thing I'd do would be to remove it and clean as much rust/corrosion off the threads that I can. If you have a bad electrical connection there, everything past that point could be suspect.
Catfish4818 - Thx for your help. I will do as you suggested. I can't start on this right away (family tasks). It may be awhile before I have an update for you.
Thanks for all your timely responses.
power windows problem
