Hey guys,
I stumbled across this incredibly helpful forum a while ago and have been reading lots of old threads here for several months already. I recently got a 1985 C20 Suburban (Silverado line) in mint condition, which isn't that easy these days over here in Europe. As everything else was more or less the way I wanted it I got the truck even though it didn't have the barn doors that I would've preferred and now I'm stuck with an unnerving issue on the tailgate window lift mechanism.
There's an old post from 2011 by garlicbread on here ( https://ck5.com/forums/threads/suburban-tailgate-power-window-repair.288063/ ) that helped me alot understanding how the whole thing works and also solving the first (and a lot more relevant) problem I had: The window wouldn't go up at all. Turns out it was just the safety release on the passenger side of the tailgate, where the connector had fallen off the terminal - doh.
Now to my problem at hand: The window moves fine when operated from the dash switch inside but won't move when turning the key on the tailgate. I know that this is a common issue and these electrical window lifts are not exactly the most reliable, but the strange thing is that I think (?) I checked every possible cause by now and still it won't work. I took the whole tailgate apart and looked at all the wires and parts, measured everything with a multimeter. The lock gets 12v power from the firewall with the ignition off and turning the lock leads to power being distributed to either of the two 'up'/ 'down' wires leading from it to the window motor. The 12.3 something power also arrives at the end of the wires leading into the motor connectors just as it should. And this is where I'm at a loss: The motor evidently works, as it's no problem to move the window with the ignition on and the switch on the dash. Why doesn't it work when it gets the same power from the same wires, only powered by / through the lock?
I couldn't find anything helpful online or in my Haynes/Chilton. As these motors aren't really available as replacement parts as far as I know and sending mine in for overhaul just on a hunch isn't really an option either (I'm located in Germany) I didn't consider replacing the motor yet.
I know this is a rather detailed request but maybe some of you had a similar problem or just tons of experience when it comes to these locks / motors? Thanks tons in advance.
cheers, Tim
I stumbled across this incredibly helpful forum a while ago and have been reading lots of old threads here for several months already. I recently got a 1985 C20 Suburban (Silverado line) in mint condition, which isn't that easy these days over here in Europe. As everything else was more or less the way I wanted it I got the truck even though it didn't have the barn doors that I would've preferred and now I'm stuck with an unnerving issue on the tailgate window lift mechanism.
There's an old post from 2011 by garlicbread on here ( https://ck5.com/forums/threads/suburban-tailgate-power-window-repair.288063/ ) that helped me alot understanding how the whole thing works and also solving the first (and a lot more relevant) problem I had: The window wouldn't go up at all. Turns out it was just the safety release on the passenger side of the tailgate, where the connector had fallen off the terminal - doh.
Now to my problem at hand: The window moves fine when operated from the dash switch inside but won't move when turning the key on the tailgate. I know that this is a common issue and these electrical window lifts are not exactly the most reliable, but the strange thing is that I think (?) I checked every possible cause by now and still it won't work. I took the whole tailgate apart and looked at all the wires and parts, measured everything with a multimeter. The lock gets 12v power from the firewall with the ignition off and turning the lock leads to power being distributed to either of the two 'up'/ 'down' wires leading from it to the window motor. The 12.3 something power also arrives at the end of the wires leading into the motor connectors just as it should. And this is where I'm at a loss: The motor evidently works, as it's no problem to move the window with the ignition on and the switch on the dash. Why doesn't it work when it gets the same power from the same wires, only powered by / through the lock?
I couldn't find anything helpful online or in my Haynes/Chilton. As these motors aren't really available as replacement parts as far as I know and sending mine in for overhaul just on a hunch isn't really an option either (I'm located in Germany) I didn't consider replacing the motor yet.
I know this is a rather detailed request but maybe some of you had a similar problem or just tons of experience when it comes to these locks / motors? Thanks tons in advance.
cheers, Tim
