My fuse for my brake lights is keep blowing. I changed out the brake pedal switch and also cleaned up the trailer harness and also the main harness that's back there. It doesn't seem to blow when my truck isn't on. Once I turn it on and hit the pedal the fuse will blow. Any help would be great.

 

Do you have cruise control ? Maybe a problem with that area.

 

Yes I do. I would think that the fuse would blow once i tried to disengage cruise though?

 

You said you checked the wiring, what about the grounds ?

Since the fuse doesn’t blow when the ignition is off what have you add or change that involved switched power ?

 

Grounds are the only things I haven't checked just because I haven't been able to find out where the grounds are even at. The only thing that runs off ignition switched power is my head unit and a small amp. I've had the wiring for at least 3 years and never had a problem with it.

 

Have you removed and reinstalled any parts from the truck, maybe a pinched wire ?

It might take checking each wire without power applied, check them to ground too.

 

That's what I was thinking I might need to do. I just wasn't sure if there was anything else that could be causing it.

 

Fuse 35 and 13 are both blowing. Fuse 35 is the park lamp/trailer tow relay. Fuse 13 is the brake pedal position switch. I'm really not sure what's going on. It seems like it would be back where my trailer connector is but I cleaned it up though.

 

And you have rechecked these connections ?
From the way you are talking it sounds like a shorted wire.
And the fact that it only happens when you have the key on implies that a relay is involved but one that is actuated when the key is on and the brake is depressed… sounds like the Trailer wiring is having a problem.
Did you do anything to the Tow Relay ?

Re-Check the wiring, again look for pinched or brken and frayed wire and check out any wires you touched.

Luck, PITA wiring...

 

Yea I'm going to recheck all of the trailer wiring. That seems like that's where the problem is to me. I haven't done anything to the tow relay either. And yes wiring is a huge PITA! I understand how it works and know how to wire up just about anything. But tracking down messed up wires and all that is something that I can't figure out.

 

Know where you are and where you are coming from…
Get a good Probe or multimeter and have at it.
Again, I like to write everything down that I find, CRS Disease (Can’t Remember $hit !) so once it is written I remember OK… maybe ADD.

Luck and let us know what you come up with.

p.s. not sure but PM “rwenzing” he is the electrical wizard and may be able to direct you in the right direction; me I am just guessing.

 

I think you and me both have that same disease! Now just to find some time to sit down and start figuring it out a little better.