OK, my 76 pasenger side window switch has been working fine until recently when you would have to wiggle the switch back and forth a few times to get it to open and the same to get it to close. Now it just plain dont work. When you operate the switch either way you can hear a faint crackle noise in the passenger side door but the glass just does not move. I tried the switch while adding a little pressure to the glass and still no go. I am at the point where I dont think the switch is the problem, so I took the door panel off and now I am confronted with the metal interior door panel and I dont know what I am looking for or what to take off.

I should also mention that the drivers side works perfectly - so I guess the glass is half full

What does this sound like the problem is and how do I get to it and fix it?

Thanks
Kev

 

I'd be looking at the switch first. If you wiggled the switch back and forth to get the window to move then your switch is defective. You can test the switch by substituting with the drivers switch.

 

Mmmm, not so easy, the previous owner had hotmelt glued the switches and wiring in to the brake console. I have some switches and a brake console on order with Willcox at the moment, but I can't do much with the existing ones.

Because I could hear a noise coming from the doors in response to the switch movement I had presumed that the switch must be working OK? Is this a bad presumption to make?

Kev

 

I just tried splicing some test leads in to the three wires going to the switch and shorted them out to test if the switch was the issue and it does the same, just the noise from the door but no movement. I suspect that whatever is not working in the door, the rocking back and forth of the switch must have given it a kick in the pants and that was why it worked sometimes.

Kev

 

Here is a link to a picture of our door with the window lift motor installed. You might want to try first checking to see if you are getting voltage to the connector plug. The plug is cut and dried two wires one will have power when the window switch is in the up position and the other will have power when the switch is placed to the down position. That will rule out the switch and relay. If you wish you can use a 12 volt source with a wire directly to the motor and it should run. Scroll down to post # 17
http://forums.corvetteforum.com/c3-t...er-window.html

 

Thank you for the photo above. Please excuse my ignorance, but is there an easy way to access the plug without having to take off the whole metal panel? Obviously in your picture that has everything removed, but I want to do the least I can.

Thank
Kev

 

No such thing as a bad assumption when troubleshooting.
This would indicate that the motor is not receiving full power and is not able to run properly.

You need to jump the switch center with one of the other wires to raise or lower. Connecting all three together will result in the motor attempting to run in both directions.

My observation was that moving the switch and getting intermittent operation would indicate a faulty switch or bad connections at the switch.

 

To test the window switch take a continuity meter, put one lead on red/white contact (color on 77 vett) take the other lead put it on tan or light blue. Press the switch in one direction if no ring, the other direction. If it does not ring in either direction that side of the switch is bad and the entire switch needs replaced. If it does ring repeat steps and touch the other color (tan or light blue). The switch must be "unhooked" from the car for this test to work.

I agree, it does not seem to be a switch problem.

I would first check the ground connection for the window motor. It could be a black wire ran to ground or done through the body of the motor. I have never had to look at mine this is just trouble shooting 101. Clean the ground connection on both ends. If the motor body (frame) is the ground remove the bolts that hold it in place and sand or file in between where the two parts meet also clean the bolts and nuts to remove any rust or build up. You need a clean metal to metal connection for a quality ground.

Then clean the hot wires tan (up) and light blue (down); (color on 77 vett).
Make sure to remove any rust or build up. Use electrical connection cleaner spray (sold at every auto store) to do this. Let it dry then reconnect it. Turn the car to on, test test the window. If it does not work verify 12v to ground from tan and blue from the wire harness. Do this one at a time tan should be up but double check by throwing the switch the other way.

If you have 12v on tan and light blue to ground it is most likely a bad motor remove it and have it tested out of the car at an auto parts store when your buying a new one.

 

Oh no, I was only connecting them one direction at a time, poor wording on my previous post

I just dont know how the circuit actually works, so if there is not enough power getting to the motor, where would it be getting lost. There must be some power making it to the door because of the noise I can here, but is there anything electrical (other than cables) between the switch and door?

Kev

 

A volt meter should read a steady 12v (or close) to ground from tan or blue.

 

Thank you for the detailed info. Would I be able to get to the moror by removing the black plate that sits over the motor? I dont have my socket set here to give it a try until I get home.

Kev

 

I went and looked in my chiltons, yes removing the plate like expose the motor. The bad news its rivoted. Your going to have to drills have new rivots or bolts and nuts to replace them.

 

I had the same problem on the drivers side. Was not the switch or motor. Was the teeth on the actuator. A new one is cheap, fixed the problem and I think I'm gonna do the passenger side next cause the drivers side goes up and down faster and smoother now.

 

Oops, misspoke the rivets are something else. It is just bolted.

 

Good call

 

Well I took off the plate that hides the motor and now everything works fine. I have checked the teeth on the actuator and they look OK I have checked the wiring and it all looks sound. Since I cant get ti to play up again I just re-built the door and I guess for now I will forget the whole issue. I dont doubt that it will come back again, but it is hard to fix something that is working perfectly

Oh well, at least its working for this weekend.

Thanks
Kev