Brake Controller Installation

Reply Subscribe

Thread Tools

Search this Thread

Sep 1, 2008 | 08:04 PM

willhf1011

Thread Starter

New User

Joined: Jan 2008

Posts: 8

Likes: 0

Brake Controller Installation

OK so I'm installing a brake box for a friend of mine and i was going in to do the wiring today and noticed that there are 3 wires sticking out of one of the harness tubes. They are all heat shrunk on the end for insulation and look to be factory. They are also red, white and blue, the same colors as on the brake box (save for the ground). The truck already has a 7 prong plug in the back with a blue wire to it for brakes, this makes me think that maybe these wires were installed factory to support a brake box if the truck came with a tow package? Anyways onto the problem, if these wires are infact for a brake box then i would like to use them for neatness of installation, problem being none of them are hot and so the box will not be getting juice, is there a fuse or relay somewhere that needs to be installed to light them up once you're ready to install a controller?

Sep 1, 2008 | 08:34 PM

DPorter

More Turbo

Joined: Aug 2006

Posts: 576

Likes: 6

From: midland, Ontario

Customer access wires for add on accessories. Not for your brake controller.

Under dash to the left of the radio should be a brake controller plug to attach to the controller. You will need the adapter plug to wire to the controller wires then plug into the
harness and you are good to go.

Sep 1, 2008 | 08:37 PM

AzBlueWolf

Post Fiend

Joined: Oct 2004

Posts: 10,418

Likes: 0

From: SpringHill,Fl

if your friend got the truck new, there should be a package in the glove box with wire pigtail, a couple relays and instructions for wiring the brake controller

Sep 1, 2008 | 08:42 PM

Greywolf

Fleet Owner

Joined: Aug 2001

Posts: 29,941

Likes: 46

From: Drummonds, TN USA

He's right - those wires should be capped off and the connector found. It may be next to the radio, but I've more often found them closer to the emergency brake.

There may also be a fuse on top of the fender liner in the engine compartment that has a dummy fuse in place, but not if it's already been used for towing. Look in your owners manual and go over the fuse designations carefully to see if there's one or two you might need to be aware of.
*The trailer turn signals are two that stand out in my mind.

That bunch is one wire short anyway. There should be a red(brake pedal switch), blue(controller output), white and black(power AND ground)

Never trust a controller to ground through its case.

Sep 1, 2008 | 08:44 PM

willhf1011

Thread Starter

New User

Joined: Jan 2008

Posts: 8

Likes: 0

does anyone have a picture of that?

Sep 1, 2008 | 08:45 PM

AzBlueWolf

Post Fiend

Joined: Oct 2004

Posts: 10,418

Likes: 0

From: SpringHill,Fl

eBay Guides - Adding Factory Trailer Brake Control To Your Super Duty

this sounds a little more expensive, but may be better in the long run...

Sep 1, 2008 | 09:54 PM

dkf

Hotshot

Joined: Mar 2007

Posts: 10,101

Likes: 40

From: Pa

I've installed a Tekonsha P3 ans Prodigy on an 03' and 04' SD. For both I paid the $10 and got the plug and play harness from Tekonsha. Plug the harness into the truck connector(Under dash below waayyy to the right), mount the controller and plug the contoller into the harness and done. I use factory plugs when I can.