Need some help with power windows....
Thread Starter
Melting Slicks
Joined: Jun 2002
Posts: 2,844
Likes: 99
From: Orrtanna Pa.
Need some help with power windows....
The next project on my never ending list........Power windows. They haven't worked in years. I wouldn't be surprised if both motors will need replaced, but in the mean time started checking out the electrical connections. I recently pulled the console, to do a face lift on that, and cleaned the window switches then,checked continuity on the switches. Both are good. There is an intermittant ground connection to the door,checking from a bolt on the shifter mount, to a screw on the actual door. I think I'm going to add my own ground wire to both doors, running through the flexible conduit at the hinge location of the door.
The real question is in the hot lead connection. I have no voltage to the common of the window switches. My shop manual shows a 76 model having a power window relay, which I assume cuts power if the ignition key is off. Have no idea if there is a relay on the 80, and if so where? The shop manual also shows an 82 schematic, which shows no relay. I don't see any fuses blown, but I'll pull them all when I get a chance to check for sure.
Any thoughts guys?
The real question is in the hot lead connection. I have no voltage to the common of the window switches. My shop manual shows a 76 model having a power window relay, which I assume cuts power if the ignition key is off. Have no idea if there is a relay on the 80, and if so where? The shop manual also shows an 82 schematic, which shows no relay. I don't see any fuses blown, but I'll pull them all when I get a chance to check for sure.
Any thoughts guys?
Team Owner
Joined: Mar 2002
Posts: 24,160
Likes: 78
It's been 6 years since I got mine working, but I can try to help. I kind of doubt you need new motors. It's pretty rare for them to burn out. You likely either have a connectivity issue or your regulators are fused in place with dried out grease and rust. The latter is what happened to mine. I don't recall the wiring schematic, but it's very common to run relays off the ignition power (as opposed to powering things directly off the ignition power). Turn key, relay closes, power to X
Since you're not getting power to the switches (assuming you have the key turned on), then yes that relay (or wiring) is suspect. Where is it? Well, look under the driver's side dash. See that rat's nest? It's one of those.
Why don't you get about 15' of wire, jam one end in the battery, and the other end in the window switch (after pulling the other power lead off of course). If they start working, that'll narrow down your problem.
Since you're not getting power to the switches (assuming you have the key turned on), then yes that relay (or wiring) is suspect. Where is it? Well, look under the driver's side dash. See that rat's nest? It's one of those.
Why don't you get about 15' of wire, jam one end in the battery, and the other end in the window switch (after pulling the other power lead off of course). If they start working, that'll narrow down your problem.
Thread Starter
Melting Slicks
Joined: Jun 2002
Posts: 2,844
Likes: 99
From: Orrtanna Pa.
I was planning on a similar test, just to test the motors, as you suggest, but the wiring will still have to be addressed for a perminent fix.
I did at one point have the rear storage compartment out, and noticed several relays there. Maybe it's one of those. I have to dig back into it. There are also seveal relays under the console, and as you mentioned the perverbial rats nest under the dash.
This may require several beers in order to properly evaluate................
I did at one point have the rear storage compartment out, and noticed several relays there. Maybe it's one of those. I have to dig back into it. There are also seveal relays under the console, and as you mentioned the perverbial rats nest under the dash.
This may require several beers in order to properly evaluate................
Pro
Joined: Nov 2008
Posts: 542
Likes: 3
From: Bloomfield Hills MI
I would also listen real close to the motors. If the window mechanism is frozen due to lack of lubrication, you'll still hear the motor 'strain' as it tries to move the window. That's a good way of confirming that you have power to the motor. Only do this to test, though. My fault was NOT in the switch but in the plug that connects to the switch - a combination of corrosion and age had led to a faulty connection on the 'up' position. I would not rule that out. BTW those plugs are a Royal Pain In The @rse to rebuild...but can be done.
Pro
Joined: Nov 2008
Posts: 542
Likes: 3
From: Bloomfield Hills MI
I was planning on a similar test, just to test the motors, as you suggest, but the wiring will still have to be addressed for a perminent fix.
I did at one point have the rear storage compartment out, and noticed several relays there. Maybe it's one of those. I have to dig back into it. There are also seveal relays under the console, and as you mentioned the perverbial rats nest under the dash.
This may require several beers in order to properly evaluate................
I did at one point have the rear storage compartment out, and noticed several relays there. Maybe it's one of those. I have to dig back into it. There are also seveal relays under the console, and as you mentioned the perverbial rats nest under the dash.
This may require several beers in order to properly evaluate................
Thread Starter
Melting Slicks
Joined: Jun 2002
Posts: 2,844
Likes: 99
From: Orrtanna Pa.
I haven't heard so much as a grunt from either motor in years. I will check the connector for sure, but at this point I am certain I do not have voltage to the common terminal of the window switch, so I know I need to find the fault between the fuse panel, and the switch.......somewhere. That's what got me thinking there might be a relay in the circuit hiding ..............somewhere.
Race Director
Joined: Apr 1999
Posts: 11,520
Likes: 13
From: CORVETTE 77 385 C.I. TEXAS
I suppose you checked the circuit breaker. I have a 77 GM Corvette El. manual which shows a diagram w/ relay under console. Though 80 may be different, follow PW switch wiring forward left side past shifter. Not a pic., just a diagram shows to be a "square" relay.
Le Mans Master
Joined: Dec 2003
Posts: 5,727
Likes: 38
From: Fremont CA
ALL power window systems have a power relay in them in C3 Vettes. The relay on my 70 is under the shift console. To test the widow motors, get a 30 amp fused test lead and touch the terminals on the rear of the motor with a postive lead, one terminal is up other is down. I have used motorcycle batteries with leads to work on motors of "dead C3's" (of which I seem to have too many of right now) one lead on termnal other on the case of the motor.
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Team Owner
Joined: Mar 2002
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I haven't heard so much as a grunt from either motor in years. I will check the connector for sure, but at this point I am certain I do not have voltage to the common terminal of the window switch, so I know I need to find the fault between the fuse panel, and the switch.......somewhere. That's what got me thinking there might be a relay in the circuit hiding ..............somewhere.
Thread Starter
Melting Slicks
Joined: Jun 2002
Posts: 2,844
Likes: 99
From: Orrtanna Pa.
I don't suppose I'm the only guy here with an 80, that is having window issues...........
I guess I'll just have to stock up on some beer, and tear into it. Shame I didn't last week when I had the console all tore apart!
Here's my latest console cover...............I wanted it to look stock,...sort of. The data plate is from a 69 427.
I guess I'll just have to stock up on some beer, and tear into it. Shame I didn't last week when I had the console all tore apart!
Here's my latest console cover...............I wanted it to look stock,...sort of. The data plate is from a 69 427.
Last edited by The Money Pit; Apr 2, 2009 at 01:21 PM.
Thread Starter
Melting Slicks
Joined: Jun 2002
Posts: 2,844
Likes: 99
From: Orrtanna Pa.
Just found the problem yesterday. There is in fact NO relay on the 80. The hot lead from the window switch goes straight to the fuse block. I checked all fuses, all tested good. So I re directed power from a different slot in the fuse block,.....both windows now work.
This took me two beers to resolve, though the windows have not worked for six years.................I have got to start drinking heavier........
This took me two beers to resolve, though the windows have not worked for six years.................I have got to start drinking heavier........
Something to consider is the PW are normally connected to a 30 Amp circuit breaker which is shown on 80 wiring diagram.
Team Owner
Joined: Mar 2002
Posts: 24,160
Likes: 78
Just found the problem yesterday. There is in fact NO relay on the 80. The hot lead from the window switch goes straight to the fuse block. I checked all fuses, all tested good. So I re directed power from a different slot in the fuse block,.....both windows now work.
This took me two beers to resolve, though the windows have not worked for six years.................I have got to start drinking heavier........
This took me two beers to resolve, though the windows have not worked for six years.................I have got to start drinking heavier........
Team Owner
Joined: Jul 1999
Posts: 65,492
Likes: 230
From: Orange Park Florida
so pull it totally outta there, and look really good at that dawg, make damn sure it's not corroded/rusted and that the plastic on the wires is intact....
Thread Starter
Melting Slicks
Joined: Jun 2002
Posts: 2,844
Likes: 99
From: Orrtanna Pa.
I pulled the T-tops out when it was hot out. The windows were up, but once you hit 55 on the highway, the turbulent air was my AC! I really can't drive this beast as much as I used to due to gas prices, weather conditions, or other commitments. The Lincoln has become my driver.......
About the relay. I metered between the common of the window switch, and the end of the pink window wire at the fuse block. Zero ohms, no relay. As for why no power.........When I get ambitious enough I guess I can pull the fuse block off the firewall and try to figure out why a 29 year old distribution block might have a bad connection. But for now,.........the windows work.
7th Gear
Joined: Jan 2004
Posts: 7
Likes: 0
From: Olyphant Pa
Don't know if you know it or not, but there is a company called Lectric Limited Phone 708 563 0400 that sells some nicely laminated wiring diagrams for corvettes. I bought one for a 75 when I had it and now have one for a 78. They are a complete wiring for the chassis of the car for the year you want. When I got mine about 2 years ago it was only about $11.00 but worth it when problem solving electrical problems.
