Hi everyone, new guy here. I need some assistance with adding a brake controller to my 2008 F-150 xl regular cab 2wd.

I bought premade wiring harness to connect a controller, but after getting it all plugged in I am getting no power to the controller.

I’ve checked the kick panel fuse in position 105 and swapped in a relay to R05. Still nothing. Is there anywhere else I need to check or add a fuse or relay?

Thanks in advance.

 

check the fuse 101 that supplies tow power.

 

Thanks for the response techrep. On my panel fuse 101 appears to be for the starter solenoid.

 

*****Edit*****this information is wrong . I was looking at a 2001 truck****
Fuse 108 is trailer tow electric brake 30 amp maxi fuse. This is the fuse box in the engine compartment.

 

Thanks. Ok so dumb question…where is the underhood fusebox? The only thing I’ve been able to find is a small rectangular box mounted on the driver side fender with a couple of fuses in it.

 

Driver side under the hood.


https://www.google.com/url?sa=i&sour...71640782017000

 

This truck is a 2008, so it’s the generation after the one in the video.

 

Oops. Somehow I was looking at 2001. Nevermind 😬

 

does 106 have a good fuse ?

 

Here is the 2008 trailer brake module diagram. Make sure your pre-fab harness matches.
The dark blue (DB) wire is the trailer brake signal.

 

Don, you’re right on track, and just came to post an update.

Last night I started the process of eliminating the less likely causes. I unplugged the prefab harness and started comparing the wire locations in it versus the truck plug.

Well, the red and black wires were put into the prefab connector on the wrong side of the plug bank!

I disassembled the plug, moved the wires over to the correct side, and now the controller has power and is working.


Thank you to everyone that assisted helping to narrow down this problem!

 

Nice! Good job.