I have a 1994 F150 with the factory tow package.
I just picked up a trailer that has brakes and I am trying to hook the controler up to my truck. I got the adaptor harness and the controler and found the plug under the dash. The problem is the blue brake wire dissapears into the dash someplace and I cannot find it at the rear of the truck. Anybody had this problem? Do I have to run it back there my self. Or did ford hide it somewhere?

 

I just did this on my '94.
When you say the blue wire dissapears into the dash and you can't find it on the rear exactly what type of controller do you have?? I wouldn't worry about a so called missing wire if in fact you have the Ford factory tow package.
You should end up with only 4 wires coming from the adaptor harness and they should match up color for color to your controller.

 

If you have the factory tow package, there should be a 7-prong connector plug mounted on frame of your truck. The plug is usually on the driver's side just about where the frame connects to the rear bumper brackets.

Just plug the trailer into the connector and plug your controller to the connection under the dash and you should be set. If your controller did not come with the plug, just pick one up from NAPA or any place that sells controllers. Make sure that you get the Ford plug to connect to your controller.

Lou Braun

 

Hey Guys...I'm right in the middle of a similar install on a '93 F-150 and have the same questions. The hook-up of the controller under the dash is a "no brainer"......but in order to power the trailer brakes we're supposed to have an additonal blue wire that goes into the 7 pin receptical. The harness on the truck only has 4 wires at the 7 pin receptical (green - tail lights, brown- right turn, yellow - left turn and white - ground . Anyone know were to get the blue from the controller? Under the dash or under the hood....other?

 

I guess I am assuming that I have the tow package because I have all the extra relays under the hood for trailer lights, and for trailer battery charging. Thank you for the input I will investigate the wire harness at the rear of the truck some more. The previous owner has the T type connector for four flat light wiring installed and It is possible they ran the wires with the tail light wiring. It was hard to tell wire color when they are all wrapped up from the factory.

 

That 4-pin flat connector is probably hooked into the vehicle's tail light wiring as you suggested. The tow package has totally independent wiring for the trailer.

The pinout for the 7-pin trailer connector follows (viewed looking at the plugs' connectors):

Pin 1 - center pin - trailer backup lamps (blue/light blue wire)

Pin 2 - 1 PM clock position - trailer battery charge (orange)

Pin 3 - 3 PM clock position - RH turn signal (dark green)

Pin 4 - 5 PM clock position - trailer brakes (dark blue) This leads from the output of your brake controller.

Pin 5 - 7 PM clock position - trailer ground (white)

Pin 6 - 9 PM clock position - LH turn signal (yellow)

Pin 7 - 11 PM clock position - trailer running lights (brown/white)

The wiring for the 7-pin connector is on the driver's side frame almost at the end. It is possible that the 7-pin connector was removed, but the wiring is still there.

Lou Braun

 

I have a 1994 f150 xl I just did a bunch of research before wireing without much success. The blue brake control wire stops at the bulkhead connector on the firewall. I ended up cutting the wire and running it through the firewall without using the oem connector harness plug. The Brake controller with the OEm harness plug adapter is plug-and-play. Still looking into the rest since the truck has relays and fuses For trailer circuits.

 

Nice necro-post. If you look above the user's name in the dark blue bar, it shows the date of the post. This is a twelve year old thread.

As it was stated in the posts above, if you really do have the factory trailer wiring package, there is nothing to cut/extend/add. You plug in the brake controller under the dash using the correct cable for a Ford, then you find the seven pin connector under the truck, left hand frame rail in front of the rear bumper mounting bracket, re-mount that in a more usable position and go.

If the seven pin connector doesn't exist, you most likely do not have the factory setup and it would be like installing the wiring on any other vehicle.

Ray