Power Windows Troubleshooting Info

C10MixMaster

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Thanks so much C10MixMaster, you've provided a LOT of great info. I appreciate it. Unfortunately, I still have more questions (sorry!)

1) Where is the circuit breaker on your 77? On the 2nd page of this thread (post #20, Jul 6, 2013 by HotRodPC) there is an attachment "FuseBox85K1500.jpg". It shows the circuit breaker as a silver box above the 20amp Yellow Choke Fuse. I do not have a circuit breaker in that location, and I don't think I have any circuit breaker on my fuse box at all. Or have you answered that question in your post #43 that says "the breaker near the brake booster", meaning that the breaker is on the firewall, not on the fuse box? If so, did you draw the smaller blue circle around the breaker in the first picture?

2) Can you please explain what you mean in your post #43 that says "then to a relay that's powered by acc. on the brake pedal assembly (behind the radio)"? You mean the relay is on the brake pedal assembly (???) Are you saying to get behind the radio to test for power between the breaker and the relay? Is that what you're illustrating in your second picture? Is your radio removed in that picture?

3) Yes, I believe someone put aftermarket doors on this truck, and that they are 1982? 1982? -1991 doors. Thanks for explaining the early system vs later system. I had no idea. I gotta trace the 6 wires and see where they go...


1) yes the breaker is the smaller of the two blue circles on the first pic.
2) yes the second pic is without the radio in the dash, and the relay is on the brake pedal bracket , you looking at the passenger side of the bracket about 2-3" behind the firewall..
 

Mark80K15

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Ok, thank you C10MixMaster, you've been a LOT of help. I'll check it out and get back to this thread.
 

USMC Hitman

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Lots of good info here. Following this thread since I have some of these issues.
 

custodian

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I've put new window motors, switches on both sides, and connectors and have been working fine in the 85 C10 until today. The passenger side works but the drivers side doesn't. So, I checked fuses, okay. Checked for power on the drivers side, NONE. I made a jumper wire and ran power from the under hood junction box to the switch, worked. I believe I have a broken wire between the door and body.

The wire loom between the door and body is still intact and not rotted and don't want to cut it open. Can another wire be pulled through without alot of trouble?
 

Snoots

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Yes. Just tie the new wire to the old one to pull it through.
 

custodian

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Yes. Just tie the new wire to the old one to pull it through.
I got around to fix the wire problem, no way to just pull the wire threw. The wire harness was wraped with tape. I had to push the entire wire harness back threw into the cab. I found three wires broke, window and both power lock wires. I had to just use butt connectors and push the wire harness back where it was. Working fine so far.
 
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TPISly-C10

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here my test bench for testing power window/door lock look like if that can help some one! ;)
 

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