power window switch on tailgate

[smittysmith13]

Reading a lot of these threads I see that the rear power window has been a hot topic from time to time. The key switch on my '87 has stopped working. I pulled the inner plate off and realized that I am going to have to pull a lot more out in order to get to it.

Can anyone suggest away to check and make sure that it is not something else before I go and yank the glass and everything else out of the tailgate.

Oh...the swith on the dash works just fine. It goes up and down (little slow) with no problems...

thanks...

 

[Muddytazz]

A common problem with the key switches for the tailgates is the contacts inside the switch. You need to pull the key switch out, tear it apart and clean the contacts up and it should work.

 

[dyeager535]

You can pull the switch connector off and jumper it to power the motor, but if you've gotten that far, might as well pull the switch out too.

 

[84ever]

I got my '84 K5 in '87 and the tailgate switch wasn't working. It's not hard to pull the inside cover off with the tailgate down, flip the safety switch by hand, then crank the window out using the dash switch. I always stick a trash can under the glass to hold it up while horizontal, it's just the right height. Then you can get to the switch.

The switch contacts were burned up, nothing left of them. I replaced the switch only to have the contacts burn up again several months later. Fool me once, shame on you, fool me twice..... There's just too much current on that motor for those cheap contacts in the switch.

I installed a pair of power relays inside the tailgate, connected the motor to the relay contacts, and connected another new replacement key switch contact to the relay coils. I think the relay contacts were rated for 30A DC. The dash panel switch still drives the motor directly, although I could have made it drive the relay coils as well.

That was over 20 years ago, haven't had to mess with it since. Oh yeah, I didn't trust the ground going to the tailgate through the hing either, could contribute to voltage drop forcing the motor to draw even more current through the switch contacts. So I added a dedicated ground wire from the frame to the tailgate as well.