Rear window operation

[Shive62]

Hello
I recently purchased a 1991 k5 . The rear window only works when using the button on the dash. Need help with troubleshooting this?? Should work with the key on tailgate? Right. Any help appreciated

 

[6872xtc]

Most likely the keyed switch in the tailgate has a bad connection to the harness or it has failed internally, would be my suspicion.
You would have to open up the tailgate to dig in and find out.
Unfortunately, you will need the window up to get to it after pulling the inside panel. My method would be to lower the glass, open tailgate to remove the inside panel and then close tailgate and glass. Then fold the rear seat down to go over it to access the wiring at the key switch.

 

[Blue85]

It's worth looking at the connectors underneath the tailgate to see if one is unplugged. Plus, you could check for power there.

 

[6872xtc]

It's worth looking at the connectors underneath the tailgate to see if one is unplugged. Plus, you could check for power there.

Since I don't remember the schematic, if it works from the dash switch, wouldn't those wires be in usable condition? There's only 3 wires, IIRC.

 

[Blue85]

I think they're all hot. 1 is constant power to the key switch and the other 2 are the lines from the dash switch.

 

[85-K5Blazer]

Chances are the internal connection on the key Switch is either gone or damaged .. see it these help you in your efforts

 

[USSkoval]

I think they're all hot. 1 is constant power to the key switch and the other 2 are the lines from the dash switch.

Correct. And if the 12v wire degrades anywhere (like at the connector itself, or where someone has tested the wire in the past) then the key switch in the gate will not operate the window.