A (long) power window trouble shooting tale.

[Mamushka]

Vehicle: 2012 F150 SuperCrew XLT, purchased new.

Problem: 2 to 3 years ago the driver’s side window would not roll down in the morning. Sometimes if I shut down the truck and opened the door (to kill accessories) and restarted the truck the window would work. As soon as it worked, it would work 100% of the time until the next day where it was a coil flip if it would work again. All other windows worked 100%. The issue started to get worse over time.

Read every post I could find about windows not working and best answer I could come up with was that the wire harness in the door might had a broken wire under the insulation due to the flexing. For some reason most 2012 F150’s have a connector in the door jam that rigidly holds the wires and when you open and close the doors the wires flex quite a bit. My truck did not have these connectors, so the wires were not subject to this extreme flexing that could break the wires. Regardless, I inspected the wires and would move the harness around while trying the window with no change. The window was totally dead until a restart.

Next best answer I could come up with was that the window switch got wet. During our frequent Florida rainstorms, opening and closing the door would allow some water to get on the switch, so I put in a new Ford master window switch as it was less than $40. No improvement.

I pulled off the door panel so I could wiggle the wires going to the motor from the switch. This would not “fix” the window if it was dead or “break” the window if it was working. Moving the wires in the door had no impact on the function.

Using FORScan I reset the BCM. No improvement.

I purchased a wire schematic for the truck. The front motor has 5 wires. Individually fused 12V constant, 12V switched (accessory), Ground and dedicated wires for the signal for up and down. The fuse was obviously good as window would usually work after restart. Ground was good as was a common ground for the system (still removed the ground, sanded to clean steel and reattached, no change.) The accessory 12V was good as the other windows worked. This essentially showed that the problem was somewhere in the door (3 wires related to the window that came into the door through the jam were all verified good) I checked voltage on the “up and down” wires but did not get readings that made sense (using a good Fluke meter). Looking at the schematic I figured out there is circuitry in both the window switch and the motor. This makes sense as the front windows have the auto up/down feature so it is sending some sort of signal vs. just a 12V “on or off”. Based on this I wanted to change the window motor. Found out the motor is part of the regulator so you have to change the whole thing. Great… Changed the window regulator with a new Ford one and… I works!... for a few months until it gets cool out. Then the same issue, mornings it won’t work.

Because of this I start trying different things and notice: Sometimes the window will start working on my morning commute. Usually after ~20 minutes into the drive (temperature issue as truck warms up?). Even more confusing, I left the window down a few inches overnight. When I tried to roll it down or up it rolled up. Did this a couple of times to verify. So it looks like the window, regardless of if I am pushing the switch up or down it is trying to roll up when it’s cold (60’s or lower). No clue how this can happen as there are separate wires for the up or down function.

Decide to change out the motor and regulator again with a Ford unit as I am beyond stumped. So far all good again, window is working 100%.

Needless to say, I’m not sure this fix will hold. I am beyond stumped at this point and it makes no sense how all of this could happen. Thoughts?

[FUNWIZ]

I also have an F150 Ford truck, 1999. It appears to have a mind of its own and does similar things. Good running truck just has electrical issues inside the cab like yours. My windshield wipers come on and go off by themselves so I put in off/on switch next to the column so I can turn them off and keep them off.  My door locks didn’t work, Factory ones burn out quickly and replaced with non Ford substitute now they work great. Overtime I’ve replaced both window motors, also used replacements instead of originals, I do miss the auto up and down but I’d rather have it working then having to keep replacing motors.

OK, here’s its latest issue. When it rains, the internal electronics will not shut off. What I mean by that is, I can drive the truck bring it home and park it and everything goes off. I come back later and see that the radio is on, windows can work, but ignition is off (I hope). I have replaced the ignition switch, problem still persists. I can hear a relay under the dash click a few times and then the radio comes on. Crank the truck up run it a minute turn it off everything goes off, then in a few minutes later the radio comes back on by itself. Can drain the battery down overnight. Seems to have a mind of its own.  Once the atmosphere dries back out it acts normal again. There is no leak inside the cabin that I can find. When I’m done using it now, I just unplug the battery. Somewhere there is probably a computer that controls everything thats gone flaky, hopefully it doesn’t control the airbags or brakes.  Someday you’ll figure out your problem as well, or just rewire that particular area that you’re having trouble with.

[Mamushka]

I also have an F150 Ford truck, 1999. It appears to have a mind of its own and does similar things. Good running truck just has electrical issues inside the cab like yours. My windshield wipers come on and go off by themselves so I put in off/on switch next to the column so I can turn them off and keep them off. 

This is a known issue, it is usually related to the multifunction switch (turn signal switch with the wiper controls on it). Went bad in my 1997 and 2012 F150's. Not hard to replace and not overly pricy either. The rest of your problems suck, especially the battery drain. I've heard that the door switches flake out turning the interior lights on but obviously yours is worse with the accessories turning on.

You ever use FORScan?

https://forscan.org/home.html

Free (well, you have to buy a USB to OBDII adaptor) and you can have nearly dealer level diagnostic ability. You might be able to find what module is turning on. You can also adjust a bunch of things, speedometer correction for gear change, allow fog lights to stay on with high beams, etc.

[k7]

body control modules suck. just plain suck. they cause the weirdest issues.

for the window motors...punch the door. lol. i punched my mini cooper door, and the driver side window motor would go without an issue for about 3 to 5 months. motor stops working? punch door panel again. and you're good for another 3 to 5 months.

i've had to replace the passenger window regulator in my honda element 4 times. damm annoying, but i've owned it for 10 years, so i'll suck it up.

my son's focus...lol. Ford. so...his car tried to start itself. with no key. came out to a dead battery.

charged it up. heard the starter crank real quick. wft? 4 minutes later. no key. starter kicked over again.

for me, just a weak ass battery. but i've never had a car try to leave my driveway without a driver.

[HFK]

but i've never had a car try to leave my driveway without a driver.

Wasn't that your neighbors across the street?   

Also, BCMs, PCMs, they all suck if they get a bug up their ass and make you check things that aren't broken.

[k7]

Wasn't that your neighbors across the street?   

nope. that was a dude who drove a car to my neighborhood, parked it there with 2 flat tires, walked
in my neighbor's back slider, took the keys, then proceeded to sit in the neighbor's car, with it running,
doing "something"...for about 30 minutes before he finally drove away.

all on my security video. the car he left with flats, was registered in east boynton. i think drunk dude
drove towards home, hit stuff, popped tires, burglarized a home, and stole a car in the slowest method
you could do it in. probably woke up to cops (and a stolen car) that he doesn't even remember.

florida man

[HFK]

I thought years back a car got loose from across the street and hit one of your vehicles but there was no clear proof even though it was kind of obvious.

I still use an 01 F150 for work most of the time but it has power nothing so despite everything else I have fixed over the years no electronics problems. Too bad the underside is so rotted away or I would keep putting money into it.

[k7]

I thought years back a car got loose from across the street and hit one of your vehicles but there was no clear proof even though it was kind of obvious.

oh, that. the younger sister (no license, 20 something) backed the family van into my mazda miata, caused about $3000 in damage, caved in the fender and passenger door.

and the paint transfer was there on my car, and poorly wiped off on the van. those f-ing people are the reason i got security cameras.