2006 Ford F350 With OEM Brake Controller Not Reading Trailer

Updated 07/09/2012 | Published 07/04/2012

Question:

I have the factory tow command on my truck. It shows trailer disconnected and or fault when the trailer is connected. I loaned my car trailer out and when I got it back the trailer plug was tore loose. I got on your web site and wired it back the way your diagram showed. The wiring on the trailer was working fine with no problems before I loaned the trailer out. The wires on the trailer are white, yellow,green ,brown,and a red. I dont have a 12 volt battery or reverse lights. I can hear, and feel the brakes on the trailer engauge. What have I wired wrong.. Thanks

asked by: Gale M

Expert Reply:

When using the wiring diagrams you speak of, it is important to remember that wire colors can vary, and it is best to wire by function rather than wire color.

The easiest way to determine which wiring circuit preforms which function is to use a car battery, ground the white wire from the trailer connector lead to the negative battery terminal, and apply 12 volts to each of the remaining circuits in order to determine their function. By going this route, you can be sure that the connector is wired correctly. Be sure that the white ground wire on the trailer connector is securely connected to the trailer frame.

Check the trailer connector on your truck, as well. If you can see any green or white corrosion on the pins of the connector, there is a chance that the corrosion has spread to the interior of the connector where the wires attach to the terminals. This can prevent the proper signals from passing through the truck-trailer connection, and could prevent the OEM trailer connector from reading the trailer.

expert reply by: Mike L