I have a 2000 f-250 with the tow package. I found the plug under the dash for the brake controller but what wire does what? I dont have the adapter supplied by ford.My plug has 6 wires. Thanks

 

bttt

 

The easiest thing to do it to get a Ford adaptor harness from the company that makes your brake controller. Here's what this harness looks like. The Ford harness in this link might be universal for all/most of the brake controller manufacturers, but I am not sure. Give me the make/model of your controller and I can make sure. The harness is very easy to install, just plug one end of the harness into the brake controller and the other end into the socket under your dash. If you have 4 wires coming out of the back of the brake controller (and you can't unplug the wires from the controller,) you can get the harness in the link above, cut off the connector that would go into the controller, and plug the other end into the socket under your dash. Then you just need to splice the wires from the harness to the wires on the controller. However, you might be able to find a cheaper Ford harness that does not have the plug for the brake controller.

The colors should be standard for all Ford vehicles with the tow package,
This web site explains which wires do what. In the table, I think the "OE Harness" column describes the colors of the wires in the truck and the "Brake Control Wires" explain the colors of the wires that connect the brake cotroller to the harness that's already installed in your truck. If you do not get a harness made by Ford Motors, the wires will probably be the standard colors (Red=12v power / Blue=Brake signal to trailer / White=Ground / Red=Stop Light singnal from the truck). No matter how you connect the conroller, just to be safe, I would test each wire with a voltmeter to make sure that you know what each wire does.

If you're still not sure how to proceed, I would have a trailer shop other knowledgeable entity install the controller for you.

Good luck!