Dirty Carpet

New to forum since I haven't had issues with my 2008 F-150 FX4 SuperCrew.

Currently I am unable to lower the Left Rear Door Power Window. Neither the Driver's Switch nor the Rear Door Switch works. I have never had any issues with any of the Power Windows.

On another note, the speaker in that same door never worked (didn't want to tear apart a door for 1 out of 6 speakers) and will look at fixing that also.

I took the door apart and here's what I have.

Unplugging the connection (two wires - inside and outside) at the window motor and checking with a Voltmeter:

Rear Down Switch depressed sends 11.6V to outside wire and 0V to inside wire.
Rear Up Switch depressed sends 0V to outside wire and 11.5V to inside wire.
Front Down Switch depressed sends 11.6V to outside wire and 8.2V to inside wire.
Front Up Switch depressed sends 0V to outside wire and 0V to inside wire.

Also when I plug everything in:

"Click" when I depress the Rear Up Switch (this is the normal click when the window is all the way up).
No "Click" when I depress the Front Up Switch.

1. Both Rear Switch voltages seem to make sense if everything was working.
2. Both Front Switch voltages seem to have issues.
3. The Front Up Switch not giving voltage is causing the missing "Click".
4. Even with correct voltages from the Rear Switches, would the faulty Front Switches cause the Power Window to fail?

It seems like I might have switch issues AND motor or regulator issues? I know with the interconnected wiring there are probably things I don't quick understand.

Don't want to spend money replacing the wrong thing.

Thanks for any help.

techrep

iTrader: (1)

Swap the switch with the right rear door..check that out.. Sounds like you have the power to the motor, which would tell me the motor is bad. You can also run 12vdc straight to the motor to verify..

izzysplace

Get a cheap Master switch and try that, mine failed and did all kinds of funky stuff like yours, rear switch tested fine but front switch caused the rear window to not respond (front master was water damaged and the window "lock" button along with button for the rear were bad) Lock button/switch was the cause of my rear window not working.

techrep

iTrader: (1)

I would think it he had a bad lock switch ...none of the windows would work except the drivers and the lock switch would prevent power getting to the rear window motor...which he says he has.

izzysplace

You would think right? I am right there with ya on that but that is what happened to mine, all windows worked except the right rear, Rear switch tested working, Master switch tested bad for both window and lock. I should have mentioned the Lock did not make a difference either way locked or unlocked, 3 of the 4 windows worked.

techrep

iTrader: (1)

Roger that.. new master panel then... they are a known problem in our trucks.

Dirty Carpet

So I took the advice of izzysplace and techrep and bought a new Master Power Window Switch. Put it in and still can't roll down rear window with either switch.

Took Rear Right Door Switch and tried it in place of Rear Left Door Switch and still neither rolled window down.

Back to Voltmeter with new Master Switch in place.

With the Lock Button Off (Rear can control windows), I got the same Voltages as I wrote in the first post.

With the Lock Button On (Rear can't control windows, I didn't test this before), I got:

0 Volts from Up and Down on Rear Switch (makes sense since Lock is On)

11.5 Volts on Outside Wire when pressing Down on Front Switch
0 Volts on Inside Wire when pressing Down on Front Switch
0 Volts on Outside Wire when pressing Up on Front Switch
0 Volts on Inside Wire when pressing Up on Front Switch

I also tested the continuity in BOTH switches.

Testing the Switches themselves - it seems there are no differences between the switches.

Also seemed to have continuity where they both should when switches are activated.

Still confused. Seems like I still have electrical issues with new switch.

1. New Switch could be bad from factory? But each individual window switch seem to be fine? And test OK?
2. Still have a issue with the Motor and/or Regulator? How can I tell which?
3. Or wiring? Where should I start? Can't see any issues initially but will look deeper.

Any help would be appreciated. Thanks.

izzysplace

You mention swapping the rear window switches, did you try putting the left switch into the right switch location and putting the right switch in the left position? Also have you by chance checked the wiring in the flex? If your getting nothing at the rear switch I would really think it is wiring. Now where the wires have an issue is the problem. Do you have a line tester that can pierce the insulation? you are going to have to check the wires that leave the Master switch and go thru the body to the rear door. I know Nissan Titans had a lot of issues with the Flex in the rear door having broken wires and since you could not see them because the flex people were pulling out hair going mad. You mention as well that the speaker in that door has never worked and since I missed that the first time around I would most defiantly trace the wire loom in the door to the Flex and see if the wires are damaged there. Sorry the master switch did not solve your issue.
GL with the fix

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