For some reason my rear brake lights will not turn off. The turn signals work. When I press the brake, I see no change thus indicating that the brake lights are the ones that are on.

i have checked all fuses and they are good. I pulled every single relay and it didn't effect it. The only way I could make it go out was to unplug the sensor on the brake arm itself. This is the sensor that lets you shift out of park. I messed with the plunger switch and that seemed to make no difference.

FYI, I was having some trailer light problems this weekend and had to replace a few turn signal fuses. The last fuse that I replaced was the #2 fuse that controls the rear brake lights. It is not blown now.

2005 F150 Screw.

Thanks!!!

 

Did you check the fues under the hood

 

When you say you messed with the plunger what do you mean? Did you check with a meter to see if the resistance was was changing as you pushed it and released it. If the contacts inside are staying closed even when you depress the plunger the brake lights stay on. Did you pull the bulbs out and leave them and verify that the brake light is actually on even if there is no change in the light when pushing the plunger doesn't mean the Brake light is actually on.

 

I checked every fuse and every relay on the whole truck. I didn't go so far to check the plunger with a meter.

To top it all off, after I was done pulling fuses and relays, now I have no power to the dash, a/c clutch never engages, and my windows don't work. Efff!

Anyways, I dropped it off at the dealership this morning. For some reason I thought these trucks had a 4yr 50K warranty....Wrong! 3Y/36K.

Oh well...they're gonna charge me $40 to troubleshoot and tell me whats wrong.

I guess it's time for a new truck!

 

The 2007+ have the 3 Year/36k Bumper to Bumper and a 5 Year/60k Powertrain Warranty.

 

I took the truck back from the dealer. They were 85% certain that a new "junction box" aka fuse box assembly would cure all of my problems. I'm not gonna let them experiment on my truck for $400. They said that there was a short in the box and that it needed a new one.

I'm gonna pull the box and see if I can find where the short is myself. Does anyone have a schematic of the fuse box and/or wiring schematic for the entire electrical system?

Thanks!

 

I don't think it's the fuse box, sounds more like the switch on the brake pedal is shorted causing the brake lights to stay on.

If the fuse box is melted you better unhook the battery cause your going to have a fire.

 

It turns out that in the process of me pulling all the fuses and relays, I just so happened to put the "instrument cluster" fuse in the wrong slot. There was no effin fuse in there! That what caused all my gauges, radio, windows, etc. not to work. I replaced the fuse and I was back to square one.

After pouring over the wiring schematics for the truck, I narrowed it down to the brake pedal switch (as was suggested by many). At first I thought that there were two switches. The plunger actually turns out to be tied to the cruise control. After I removed the actual brake pedal switch, I disassembled it. On set of the contacts was messed up. There is a little piece of plastic that holds the arm away from the contact that was broken.

I shimmed a piece of paper (lottery ticket) in between the contact and the arm and reassembled the piece. I installed it and now my brakes don't stay on. YAAAAYYYY!

So tomorrow morning, I'm heading up to the Ford place to speak my mind to them. It's pretty sad that their "trained" techs couldn't figure out that it was missing a fuse to make everything work. Instead they just wrote it off as a bad junction box worth $400 in parts and labor in hopes of "fixing all my problems".

Believe me, I don't think I will ever go back to this dealership for any work. In the time that I have spent diagnosing the problem and chasing stuff based on their misinformation, they should be paying me $400.

Sorry for the rant....It just frustrates me. At least now I know the problem and can now fix it.

Cheers!

 

Hmmm, interesting. Instead of first looking at the stoplight switch, you start pulling fuses? I don't know who taught you you how to diagnose an electrical problem, but it's safe to say they didn't know much.
Then you can't figure out which is the correct fuse to pull looking for a circuit that wont shut off?
Now it's the dealers fault that you couldn't put the incorrectly pulled fuse back in the slot it came from?
I'll bet you didn't bother to inform the service writer that you had spent hours "working" on it and the tech may want to thoroughly check everything just to look for mistakes/problems you may have caused, in addition to the original problem, did you? I thought not.
Buy yourself a Haynes or Chiltons. They're made for people that have no clue how to repair a vehicle.
In the time you just spent reading this, most on this site would've had the problem nailed w/o pulling one fuse.

SL