I believe that the testing so far has shown that power is getting to the yellow wire that supplies power to the motor and relays. Power to the switch has been verified along with the main ground connection. If applying power directly to the motor makes things work then power on the yellow wire should be checked while the window switch is closed. If there is a bad connection in the power lead that would make it seem power was there while the switch is open but it would drop when the load is placed on line.
@Barkydog thank you for that information, I’ll try taking the switch apart and check the circuit board
@GeorgeSanJose I’ll try running a wire with a fuse from a battery to the motor and I’ll chase down that ground
@Cougar I’m going to check the voltage of the yellow wire with a voltmeter. I tried to do something similar earlier today, but it immediately fried my voltmeter and blew the fuse in the fusebox as soon as I made contact with the wire.
It sounds like you tried to make a voltage check when the meter was set up to measure current. Hopefully you just blew the protection fuse inside the meter.
@Cougar that’s very possible, I have a voltmeter that I use regularly at work that I will try. I’m very familiar with that meter.
You have a meter? That changes everything. Just look what you can do- if you examine the posted schematic, you will see that the relays in their normally closed position, connect both motor leads together and to chassis ground. So you can check 90% of the wiring in one simple test!
Disconnect the motor. Set meter to resistance (ohms). Short the probes together and verify it reads zero ohms (or very close to it).
Now probe between the two contacts in the motor connector. It should also read zero ohms. If it does, you’ve shown the wiring from the logic board to the motor is good and that both relays are in the NC position and those contacts are good.
Now remove one of the meter leads and connect it to chassis ground. If it again reads zero ohms, you know the chassis ground connection is also good.
You’ve already verified the YEL wire is feeding bus voltage to the circuit so not much left.
Can you answer my prior questions in an earlier post?
@TwinTurbo the damaged wires were Dark Blue and Brown. I checked for Power with a voltmeter, and I had a strong connection.
UPDATE: I managed to fix the passenger side front window. I cut the wires (Dark Blue and Brown) that run from the plug (that connects to the motor) into the frame (I haven’t chased them down to see where they end). I then connected the wires from the plug to the same colored (Dark Blue and Brown) wires that come from the door switch. The motor is now connected directly to door switch.
What I believe happened is the owner before myself had an alarm on the truck that was connected to the windows and when they removed the alarm they cut the wrong wires and and connected the now dead alarm wires to the motor. Although, that’s just a theory …
I’m currently testing my rear window motor. I’m currently under the impression that the rear motor is burned out because I have power to the motor but it’s now working .
There Must Be A Master Switch On The Driver’s Door That Controls All Windows, Right?
Does it control that front window that you repaired to work?
CSA
From what you say there it seems you now have powered the window motor from the dark blue wire instead of the yellow wire. The relays are now bypassed. If that is the case I would suggest you change things back to the way they were. I think the real trouble you are having is with the yellow wire. You say you had power on that wire but I’m not sure if you made that test while the circuit was active. If there is no load on a bad connection power will seem okay, but when the circuit is active (current flowing) then a voltage drop will happen on that wire at the bad connection and the proper power needed by the load can’t get to it. The bad connection is in series with the load.
If the original design actually used the relays, then I predict your fix is short lived. The actual buttons are not meant to carry that kind of current directly and will fail in time. Then you’ll be faced with replacing that board as well.
If the rear motor isn’t working with power directly tied to it that doesn’t necessarily mean the motor is bad. The window may be jammed, like the TSB stated. Check the resistance of the motor windings. They should have a low resistance reading if they are good.
A way to test that is to disconnect the rear window and hold it in place in the up position. Then raise and lower the regulator. If it doesn’t work, that points to the motor. If doing the job alone, the window can be held with duct tape.
If what’s @TwinTurbo 's saying is accurate, that the OP has bypassed the relays, and all the current needed to run the motor is now going through the door switch, I have to agree with my eminently knowledgeable colleague, that’s not a workable fix.