power window help

[RWilliamsGa]

On my sons 88 GMC dually lr door window goes down but will not go up motor is good can run up and down with jumper wires tried switch from other door I know its good other window works perfect same thing will go down but will not go up could something be wrong with front switch causing this problem . Also have read something about a relay if it has one could this cause the problem where is this relay located

[classicchev]

Relay is under the dash, left side kick panel. Beside the ground "panel", at least on the 91 suburban it is. Maybe try a different switch and see if that works.

[tucsonjwt]

Wiggle the wires at the switch connector. These wires stab in from the sides and get loose/broken. I went through all of the switch/relay/motor/regulator options before I found this problem. If you need a harness post here and I will let you know how to get a general purpose switch harness/connector - which is the only option available now - specific OEM discontinued by GM -general purpose still available from AC/Delco.

[N2TRUX]

Welcome to the forum RWilliamsGa.

[joe231]

There isn't a relay for the windows. The lock circuit has a relay.

All the window wiring goes through the big 4 window switch. My guess is that is where your problem lies.
Posted via Mobile Device

[RWilliamsGa]

I also had concluded the problem most likely is in the 4 switch control in the drivers door here is a time saving tip I saw this morning while searching this problem next time while at your favorite bone yard cut a power window plug with as much wiring as you can will save you a lot of time checking window motor plug on motor in door get a battery or jump box put one on postive one on negative motor should go either up or down reverse wires will go other direction if not motor is bad will save taking motor out to check or in my case roll window up it was a pain to get out with window down only to find out motor was good

[tucsonjwt]

You must live in junkyard heaven. Here in Tucson the only power window harness I could find was too pricey - the guy wanted like $70 for it, and it was junk. I bought a new Delco harness and plug for $23.

[87chevy.com]

if you know your motor is good the problem is either the switch on the door panel or the contacts that go into the switch. I had a problem similar to yours. the motors were brand new gm a/c delco and were about a year old and the window was super slow going down, and somewhat ok going up. my problem was the wire terminal had 9/10 strands broken so the contact was no good. I simply bought new terminals, criped them, and I was done, window works as it did in 87.
clint

[turner16]

So I got my power windows working in the donner truck (86) and have started to install the doors in the 80 truck. Is it just me or is it a pain in the you know what to remove the power lock relay on the crossover cable? I can't even see how its connected to the fire wall in the dash? Any help would be great!

[joe231]

The lock relay should be mounted to the brake support with 2 screws on the top.
It is a royal pain to get to.
Posted via Mobile Device