Power Windows Troubleshooting Info

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

C10MixMaster

Full Access Member
Joined
Dec 6, 2016
Posts
756
Reaction score
1,428
Location
Kingman AZ
First Name
Ben
Truck Year
1977
Truck Model
C10 BIG10
Engine Size
ZZ4 350
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

Full Access Member
Joined
Apr 18, 2021
Posts
98
Reaction score
65
Location
Sicamous, BC
First Name
Mark
Truck Year
1980
Truck Model
K15
Engine Size
350
Ok, thank you C10MixMaster, you've been a LOT of help. I'll check it out and get back to this thread.
 

USMC Hitman

Junior Member
Joined
Dec 22, 2020
Posts
11
Reaction score
18
Location
Phoenix
First Name
Chris
Truck Year
1988
Truck Model
GMC Jimmy
Engine Size
5.7L V8
Lots of good info here. Following this thread since I have some of these issues.
 

custodian

Full Access Member
Joined
Apr 15, 2016
Posts
959
Reaction score
556
Location
Catawba
First Name
William
Truck Year
1973, 1985
Truck Model
C10
Engine Size
5.3 LS, 350
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

Full Access Member
Joined
Jan 23, 2013
Posts
8,884
Reaction score
18,741
Location
Georgia
First Name
Roger
Truck Year
1973
Truck Model
Jimmy Sierra
Engine Size
350 w/203
Yes. Just tie the new wire to the old one to pull it through.
 

custodian

Full Access Member
Joined
Apr 15, 2016
Posts
959
Reaction score
556
Location
Catawba
First Name
William
Truck Year
1973, 1985
Truck Model
C10
Engine Size
5.3 LS, 350
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.
 
Last edited:

TPISly-C10

Full Access Member
Joined
Apr 1, 2019
Posts
615
Reaction score
883
Location
Boucherville QC Canada
First Name
Sly
Truck Year
1986
Truck Model
C-10 shortbox
Engine Size
LQ4 6.0L
here my test bench for testing power window/door lock look like if that can help some one! ;)
 

Attachments

  • _DSC5163.jpg
    _DSC5163.jpg
    172 KB · Views: 120
  • _DSC5165.jpg
    _DSC5165.jpg
    171.7 KB · Views: 117
  • _DSC5166.jpg
    _DSC5166.jpg
    144.3 KB · Views: 117
  • _DSC5167.jpg
    _DSC5167.jpg
    119.9 KB · Views: 118

Siningbd

Junior Member
Joined
Apr 16, 2023
Posts
5
Reaction score
18
Location
41051
First Name
Brian
Truck Year
1990
Truck Model
2500 Suburban
Engine Size
350
Was able to prove out today that I've got a broken ground from the drivers switch back to the harness. Has anyone gotten creative with wiring solutions or is it best to just simply pull the harness back through the door splice it back together and pull it back into position?
 

Grit dog

Full Access Member
Joined
May 18, 2020
Posts
7,090
Reaction score
12,473
Location
Auburn, Washington
First Name
Todd
Truck Year
1986, 1977
Truck Model
K20, C10
Engine Size
454, 350
Bringing this back up. Power windows just went dead. Coincidentally after replacing the heater core.
Made sure the pink and orange wires out of the fuse box have power. Circuit breaker on fuse panel has continuity.
AFAIK they worked the last time it was driven.
Wires are in proper oe locations on fuse panel although windows always worked with the key off. (I figured someone moved the link wire to an always hot plug on the fuse box , previously, but the pink wire is on an ignition controlled pin.
So window power may be pulled from somewhere else?
Any suggestions are appreciated.
 

Grit dog

Full Access Member
Joined
May 18, 2020
Posts
7,090
Reaction score
12,473
Location
Auburn, Washington
First Name
Todd
Truck Year
1986, 1977
Truck Model
K20, C10
Engine Size
454, 350
Also the pink switched wire has on off power w/ ign on off even with the circuit breaker pulled. Weird
 

Latest posts

Forum statistics

Threads
44,416
Posts
957,128
Members
36,753
Latest member
TheRigLivesOn
Top