Window electric questions.

Selahdoor

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Here's the haps...

Here is the wiring diagram for the power windows on my truck.
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Narrowing it down to JUST the driver's side window...

As you can see there is a blue with black wire, that has power when the ignition switch is on.

There is a black wire that is always ground.

There is a yellow wire that goes to the window motor.

And in the diagram, the other wire to the motor is red. But on my truck it is white with a black stripe.



Here is what and how I have tested so far...

Motor is very strong. Looks like it was replaced recently.



Continuity on the white with black, and the yellow, are both good. All the way from the switch to the motor.

Black is good for ground, always.

Blue with black only has power when the ign is on.



Motor works to roll down. Will not roll up.


Using test light...

ign on = power to blue/blk. Push switch... Power is now coming from yellow. Window is still not working.

On further testing, I have decided for now, that it is the switch.

Pulled the switch, the connections are pretty corroded on the side where ground would be in the up position.

I'll clean up all the connections, grease them, and put it back together.

But before I do that, I'll take the actual switch apart and well. Clean it grease it put it back together...



Now here is the question...

With the ignition off.

With my test light connected to power. (So if I touch it to a ground, it lights up.)

EVERY SINGLE WIRE on both of the windows switches lights the light.

So in other words, with the ignition switch off, every single wire, including the blue with black stripe... is a grond.

How can that be?
 

dgr

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Looking at that wiring diagram, it appears the switch functions as follows

Up, switch leg 1 to hot and switch leg 2 to ground
Down, switch leg 2 to hot and leg 1 to ground.

That's obvious

I think it's easier to see what's going on by looking at the passenger window circuit. It's designed to have a second switch that doesn't have the ground. How does that switch work? It must be receiving the ground from the other switch.

When the lower switch (in the diagram) is switched, it disconnects one wire from the top switch and applies power to it. When it switches the other way, it disconnects the other wire from the top switch and applies power to it.

That would suggest that the yellow/BLK and red/BLK are connected to ground when the top switch is in the neutral position. Just like the yellow/red and red/yellow must be connected to the respective yellow/BLK and red/ black for the top switch to function through the bottom switch.

Tl/Dr. The wires to the motor are connected through the switch to ground in the resting position.

My best guess
 

david85

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Regarding why you see ground with the ignition off at all the wires, I suspect it's in the circuit upstream of fuse #14 (not shown on the schematic).

A single-throw, double pole relay or switch could have an at-rest condition (de-energized state) that ties this line to ground. When the ignition is on, it ties this line to power (these are designed mechanically in such a way that it can only be one, or the other and never both). And since we know the power windows shouldn't work with the ignition off, it makes sense. As for why it was designed to tie the line to ground, instead of simply leaving it open (not grounded or powered), there might be a reason for that but I think the supply circuit is working as intended.

Are you able to jump power directly to the motor to force the window to roll up reliably? How are sure the motor is healthy?

The reason I'm asking is it's possible the motor's internal circuit breaker is opening when you try to roll the window up. Inside the diagram for the power window motor in your schematic, there is a symbol labelled "CB". This is an inline circuit breaker that will open if it detects too high a current. It works the same as the resetable breakers in your house, only much simpler. If this is defective, you could have enough current to lower the motor, but not enough to raise it because now the motor has to lift the weight of the window, drawing more current. Normally the CB shouldn't open under normal use, but if it's defective, it might be the problem. If however, you're able to force the motor to roll up by jumping power directly to it, then disregard this theory. the CB is internal to the motor, so if the motor works under rollup loading when you hot-wire it, then it's not the CB.
 

Selahdoor

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Yes. I jumpered the motor to get the window to roll up, yesterday. Motor is strong and looks new. It HAS been replaced. Someone cut up the sheet metal to get to the bolts, instead of just drilling holes.

Thank you for the explanations of the ground perplexity.

I continued testing, and every wire everywhere seemed to be doing exactly what it was supposed to do.

It came down to the switch.

I took the switches completely apart. I mean completely. Gutted them. Cleaned and greased everything. Got it all back together. Still the same problem.

So it left me guessing maybe I was wrong about the wires.

As a last resort... The passenger side switch was working. These switches can each be individually unplugged. I did so, and swapped the window switch from the passenger side, with the driver's side switch for the driver's side window.

Driver's window worked perfectly. Passenger window still won't work from driver's side.

On a whim, I took apart the door lock switch from the passenger side. Same guts.

Swapped guts with the driver's side switch for the passenger side window. Now the passenger window works.

But the locks don't work. LOL Just like the windows, they now work one direction, (unlock), but not the other direction. (Lock.) For the best. I can't pull up on the lock stems, but I can push down on them.


I'll live with this until I can get new switches.
 

chillman88

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For the best. I can't pull up on the lock stems

Fyi they sell the plastic pieces with a mushroomed head on them so you can grab them. I have them on my crew cab. I believe they're a Dorman part, I think I got them from RockAuto
 

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