Brake Controller/Brake Light/Etc. Issues

[jmr3]

I had a wierd situation with my 05 F150 last week.  I pulled the 993 to Summit and unhooked the trailer without problem. I drove the truck without the trailer for 1.5 days without problem.  When I got to the track on Friday morning my truck brake lights stayed on and I found that the brake controller had powered up w/o the trailer being plugged in???  I tried plugging the trailer plug into the truck and that didn't help.  I pulled the fuse for the controller and the brake lights began to function properly again so it must be something with the controller/wiring. I put the fuse back in later and all seemed fine. Drove home with the trailer and 1/2 mile from home (thank god) the same thing happened again. When the brake lights go on the electric trailer brakes do too so thank god I was close when it happened.

I am not really sure where to start here. The brake controller usually only turns itself on when the trailer is plugged in. Also, the controller is somehow telling the truck that the brakes are on when they are not.  Somthing tells me this is a wiring/ground issue and not a controller issue.

Any help will be most appreciated.

[ccm911]

Looks like you'll be coming over to my garage this weekend for some troubleshooting.  Which is only fair, since I still have your multimeter.

[LouZ]

John

 

What type of controller do you have, did you recently change the mounting position or angle? If it is a pendulum type, it may be periodically getting stuck in the "on" position.

[jmr3]

Good thought Lou.  I will check that out.  The first question is how is the controller powering up on its own without the trailer being plugged in?

[LouZ]

jmr3 wrote:

Good thought Lou. I will check that out. The first question is how is the controller powering up on its own without the trailer being plugged in?

I have a Prodigy, and it powers up each time I start up (2 red lights go on). It stays powered for about 15 minutes after I shut down.



The Prodigy has a slide bar on the front that activates the circuit, when the trailer is unplugged, it displays "n.c.", but the truck's brake lights don't come on.

[rcsmith611]

Is the brake pedal switch sticking in the on position? This would be telling brake controller it should be on and leaving brake lights on as well. 

When you say powering up, what is happening?