Occasionally the driver door window switch for the front passenger door on my 05 SCREW will not work. The window can still be operated from the front passenger door switch when this happens. All other windows work normally.

The other day this happened again, so I took the driver door master switch apart to clean it up. The contacts were very dirty. I cleaned them until they were shiny and then put a little dielectric grease on all the contacts to promote continuity. I reassembled the switch and put it back in the truck. Not only did the same problem with the front passenger window persist, but now NONE of the windows work.

I know power is getting to the switch, because it lights up with the headlamp switch. Also, when any of the buttons are pressed, all the door window switch lights throughout the truck go out until the switch is released. None of the windows will now work from any switch.

At this point, I figured the switch was just bad so I ordered a new one (Dorman). I installed it today and still have the exact same problems. Obviously there is a problem with the truck and not the switch.

I bought some electronics spray cleaner and sprayed the harness connections where they go into the switch. I used nearly an entire can and still none of the windows work. I removed the body harness at the A-pillar and also sprayed that liberally with electronics cleaner and still nothing....

At this point I have no idea. I'm guessing it's likely that the Body Control Module went bad? Anyone have other ideas?

 

Not that it matters now, but dielectric grease on contacts is a no-no, it insulates, it doesn't promote continuity. That's why you only put it in the cop boots, not on the contact springs.

Just because the lights work in the switch doesn't mean it's getting primary power - different circuit. You have to get a wiring diagram and probe the correct wires.

I'd suspect a problem in the wire bundle between the cab and door.

 

Actually the manufacturer website recommends it for all electrical connections. Either way, the problem is not with the switch since I replaced it and the new one does the exact same thing. Unfortunately it's raining and is supposed to for the rest of the day. I'll likely have to wait till Wednesday to pull the door apart.

 

I popped the master switch out of the driver's door and tested with my multi-meter. I'm more confused than ever now. What's happening doesn't seem possible.

I found a wiring diagram here, and it appears to be correct with the color codes of the wires I tested:



The solid black wire is a good ground when not plugged into the switch (interestingly it doesn't show any continuity with ground when the switch is plugged in).

The Light blue wire with black stripe is battery voltage with the key turned, as it should be. This is the main power wire.

The white wire with black stripe is 0V normally, and with the driver window switch in the down position, shows battery voltage, as it should. The window, however, will not roll down.

The same thing happens for each window. Power is going through the switch, but the windows do not work.

Again, when any switch in the truck is pressed, all the switch lights go out.

So, I am getting a good ground. I am getting power through the switch when I should be, and yet none of the windows work. The switch is not defective because it is doing the exact same thing as the old switch.

It appears that every single power wire for every single window broke at the exact same time. This is impossible. There has to be something else going on here. I don't see in that diagram where the body control module is even wired to the windows, unless it's 100-3 at the top right of the diagram. Even then I don't see how that would have any control over this circuit.

 

This post appears to be similar to my problem, except that with the switch unplugged, testing the solid black wire at the switch harness, it is a good ground. I guess I'll have to run another wire to a known good ground and connect it to the solid black wire and see if that fixes it. What a PITA.

https://www.f150online.com/forums/el...-problems.html

 

OK, I verified the problem. It's a bad main ground wire (solid black wire). I don't know why I get continuity when it is not plugged in, but when I jumper a wire from ground into this wire, all the windows work. I still cannot control the front passenger window from the driver's master switch, so there is likely more than one wire broken in the joint between the door and the A-pillar. Have to wait for a day without rain to get it fixed right.

 

I spliced a temporary ground wire from the solid black wire at the switch harness to one of the door skin mount bolts. Windows are working for now...

 

That was your major clue that you have a ground issue.

 

I had kind of figured that, so I wiggled all the wires I could find, hoping to see some change in that way that wire was reporting as having a good ground. No change whatsoever. I would have thought that a weak connection like that would change with movement, but mine didn't.