How to Determine the Tow Package Wiring Functions on a 2004 Ford F-250

Question:

I need to know the color codes for the factory an where that certain wire goes and why it goes there. Because someone cuts the factor plugs out when they put the flat bed on. I went and bought a 7blade vehicle wiring kit for a Chevy or gmc because thats what I was told to buy. I still have wires hanging down and dont know what or where they go

asked by: Darrell

Expert Reply:

I can tell you how to determine the wire functions, but I can't tell you what the color codes are on the Ford F-250. This is because there is no standard and on the assembly line, if they happen to run out of the usual color, they use at that particular plant they won't shut down the line to wait for more. They will just go with what is on hand.

To find out the functions of the wires you would need a circuit tester such as # PTW2993 and someone to sit in the truck and go through each function while you test the wires with the tester.

There was a time when most manufactures used different wiring connectors from each other (as far as where they plug into the vehicle). Now though most have gone to the same type of connector where the wiring plugs into the back of the 7-Way trailer connector. However, further up where these harness plug into another harness is still different amongst the truck manufacturers. So, it all depends on what exactly you used or want to use, what it was designed for, and how the truck is equipped.

I have also included a link to our help article on wiring that does include numerous diagrams of vehicle and trailer side connectors and the wire locations. Please note that the colors indicated are typical but are by no means definitive.

expert reply by: Michael H