Hi All,
Im working on friends 2011 Ford F450 Diesel He has lost Brake Lights and Turn Signal/Hazards.
Turn signals work in front of truck.
Running lights are working fine.

same goes when trailer is connected on truck.

Any suggestions what could be the problem.
Thanks,,,

 

Does the high-mount stop lamp work or not?

Does that mean the trailer lights don't work or that the truck lights don't wor, no matter whether or not a trailer is connected?

Does this have a standard factory bed on it or does it have anything else: Dump bed, custom box, stake bed, or whatever? Single or dual rear wheel? All those variations have wiring differences.

 

Hi projectSHO89
The high mount lamp is not working
Truck lights don't work and no lights on trailer either.
Its standard factory bed.

I just need to get the lights back on the truck before someone runs in to it,trailer can wait,but i think once the lights on truck are fixed trailer lights will work normally.
thanks,,

 

Does the high mount stoplight work? The reason he is asking, it's hooked directly to the brake pedal switch. If it's working, then the likely culprit is the turnsignal switch in the column, or the wiring in the steering column. That area and that switch are common to both the brake lights and the turnsignals.

 

Hi Franklin2,
the high mount stoplight is not working, I will be working on this truck tomorrow and this information will help.
Do you buy chance know the part numbers for turn signal switch,and pedal switch

I will test the brake pedal switch first to see if the power is coming in and out.

 

That analysis, while correct for older trucks, is obsolete on this newer generation truck. Welcome to the 21st century!

The brake pedal switch and the turn signal switch, for example, are simply logical inputs to the digital system which then decodes the input, then activates the proper drivers in the Body Control Module which then controls the individual light bulbs. If you try the old way of troubleshooting with this system, you'll simply sit there with your head spinning because nothing will make any sense. You MUST have the schematics, the service manual AND an understanding of how the system works. Anything else is probably going to depend on luck to determine the fault.

Replacing either the turn signal switch or the brake pedal switch would be a waste of time and money, there's nothing in common at the switch level between the two functions.

 

Thanks for the correction.

 

Update I have the brake stoplight working it was the blown fuse #31
The turn signal/hazards rears are not fixed will have the dealer look at this issue as im not shore what could be.