F450 wiring fault - Diesel Forum

rudybilt · 05-01-2007, 01:36 AM

We just got a 2008 f450 where I work. The truck runs good but almost everytime you push the brake the "wiring fault on trailer" display appears on the dash, without a trailer behind the truck. It has been to the Ford dealer 3 times and they still haven't fixed it...... any ideas???? Oh and the truck tops out at 82mph @ about 3000 rpm and gets around 8mpg...

CaptSkup · 05-01-2007, 08:38 AM

Who is driving a "work truck" at 80+mph? Obviously someone who is not paying for the fuel. 8mpg at 80mph? Not bad for a 9,000+lb truck. Truck is speed limited because of the tires, that is their max safe road speed.

Dieselgem · 05-01-2007, 10:53 AM

I had something like with my 6.0 and a prodigy brake controller. It turned out to be the plug at the rear bumper. I just had to to be reinserted and locked. Maybe worth a look?

rudybilt · 05-01-2007, 10:56 AM

The guy that owns the truck is driving it at 82mph.....but that is irrelevant. And I didn't say he was driving 82 all the time, just simply stated that its top speed was 82.

dvtech · 05-02-2007, 08:14 AM

got the same identicle thing going on w/ a trk. just like yours. when i turn the turn signal onto the r. it does it & also when i turn on the flashers, it keeps flashing. going to check this customers out today. may take a while but i'll figure it out. may have to call engineers on it though. i'm thinking it may be something to do w/ the modules internal circuitry & not on the outside. could also be the multifunction sw.

LSchicago2 · 05-02-2007, 10:16 AM

On my 05, it was the brake light fuse that caused the message. LS

dvtech · 05-02-2007, 08:27 PM

Rudybilt, i'm gonna put a new module on this trk. i'm working on. could not find any wiring concerns. does have a external 7 pin plug added inside the bed. has a goose neck ball.