1986 GMC Electric Windows issue

[sumtinklever]

Greetings,
So my daughter is the proud owner of a 1986 GMC and it has what appears to be factory? electric windows. I believe the door panels and switches have been replaced at some point as the drivers side has 4 switches like a suburban or other 4 door.
The big issue at the moment is the passenger side window, I have replaced the switch, and the pigtail with the same results as what was there when we purchased the truck. The window is getting power and will roll up or down IF I SWITCH THE BLUE WIRES ON THE MOTORSIDE OF THE SWITCH. Basically i have power one way but not the other the only way to roll the window the other way is to physically switch the wires, there are two wires a blue and a brown wire that run to the actual window motor from the switch.

I know Ive got power but any thoughts as to why I don't have power both ways only one?

FWIW the drivers side window works but the switch to the passenger side does not I haven't pulled that panel.

Also has power locks but the don't seem to work either. I don't know if there is any correlation or not.

Thanks for your time, A dad trying to get her dang truck operational so she can stop driving mine and then I can work on my projects

 

[goldpack]

while you wait for someone smarter than I.

you might see if there is a troubleshooting guide on the factory service manual listed on Charm.li (in Lichtenstein). some of them have a page or 2 you can print off with a list of things to check off in order.

Free Service Manuals for 1986 GMC vehicles | Operation CHARM

Detailed repair/service/workshop manuals for many 1986 GMC vehicles, including electrical diagrams, recommended bolt torques, and estimated labor times.

charm.li

 

[Grit dog]

while you wait for someone smarter than I.

you might see if there is a troubleshooting guide on the factory service manual listed on Charm.li (in Lichtenstein). some of them have a page or 2 you can print off with a list of things to check off in order.

Free Service Manuals for 1986 GMC vehicles | Operation CHARM

Detailed repair/service/workshop manuals for many 1986 GMC vehicles, including electrical diagrams, recommended bolt torques, and estimated labor times.

charm.li

That link doesn’t seem sketchy at all….
But I clicked on it. Not sure how useful it is.

 

[goldpack]

That link doesn’t seem sketchy at all….
But I clicked on it. Not sure how useful it is.

been quoted on forums a long time,...I found it typed of often on the 300,000 member silverado sierra forum.

I have not gotten a bad link off that site,.. seen some bad files off other ones though. (use to be that you had to download to a flash drive and, make sure everything was virus free before touching it by scanning with multiple tools,...but this stuff is all online and stays there.

they have newer and older vehicles on the lemon links on the right side of the page. (I don't know why they did not post them there in lichtenstein, ...those lemon links are new this spring to Ukraine and Laos 1960-2025)...
handy if you are not paying for All Data which I have not logged into in years now, and need a free wire diagram for a friend's car.

 

[Snoots]

I am having problems with my Power windows and power locks on my 1983 Chevy K10. Both side windows don’t work and only the power lock switch on passengers side works for locks. I have replaced all switches and even bought new window motors and no luck. I have power going to the power window switches on both sides once ignition is switched on but there is only power going to the passenger side lock switch. I am thinking the orange/black wire that feeds drivers side power lock switch is the problem but could use some input. If the power lock switch on drivers side isn’t getting power, would that cause the power windows not to work on both sides also? Thanks

Windows first. I tend to get a bit verbose. So, in an attempt to keep people's eyes from glazing over, it's best to fight one battle at a time:

Voltage at the pink lead on both switches is good. But the circuit still needs to be grounded. Verify that it is - grounded - before moving on.

The entire power window system is grounded only via the black lead that runs from the LH switch to the bus bar ground block (up by the parking brake pivot). The RH window switch/motor has no direct connection to ground. The path to ground is provided through whichever power lead isn't being used to drive the motor up/down. It gets complicated. I posted the following for another member with non-functional PW's in an 83:

The ground circuit on these systems is insane. Yes, it's true that the local switch reverses the polarity in the leads to the motor. The positive side is pretty straight forward; pink (hot) comes in to the switch and when the button is moved up or down the power is supplied to whichever side of the motor is needed.

At the same time that the hot side is switched, the ground leg is also switched. But the ground leg does not terminate locally. One of the two remote power leads from the master switch takes on the duty of the ground leg.

So the negative path to ground is: out of the motor windings, back through the switch, into the harness connector, out of the connector on one of the remote power leads (which one depends on whether the window is being raised or lowered), all the way back to the driver's master switch, through that switch, and finally out on the black ground lead to the common grounding bus block.

See if you can follow this diagram (and the text above) - the red arrows indicate the positive side and the blue is for negative side/ground path:

You must be registered for see images attach

But easiest first, check that there is continuity - on that black lead - from the LH switch to the ground block.


There may be more than one wire connected to the ground block, so you'll have to physically trace them back until you find the one for the PW's.

If the power lock switch on drivers side isn’t getting power, would that cause the power windows not to work on both sides also?
No, even though the two circuits are run physically together, they are entirely independent.

The simple explanation of the window system is that all window motor leads are normally grounded at rest through the master switch. Moving the button up or down allows the 12ga pink to apply power to one lead while the other lead remains grounded. I suggest pulling that WDO circuit breaker and verifying with a test light you have power there with the key on, then using a multimeter set to ohms simply probe the door shell and the black wire at the switch connector-if you have resistance, its grounded-if it shows an open circuit then there’s a break in the ground circuit somewhere and it needs to be traced.

As for locks, the orn/blk is hot at all times but requires a ground which is provided via the lock relay which needs a good ground to the bracket which its bolts to-it grounds through the casing.

You must be registered for see images attach

You must be registered for see images attach

Review all the replies and info and post back what you find-I still think there is some broken wires inside the door boots-which incidentally can collect a fair amount of water in them too since water travels down the side of the cowl, around the hinges and directly on and in the boots if not 100% sealed from the elements.