Sorry if this is the wrong place.. I didn't know where to post it on here. I'm going to be towing an enclosed trailer with a 2004 Mustang inside of it about 100 miles this week. This will be the first tow that I do with the truck and I'm not sure what I need to get the brakes working on the trailer. The truck came with that wiring harness that's included in the towing package which I know needs to be plugged into the drivers side kick panel or somewhere around there. The other end has 4 open wires and needs to be wired somewhere.

Where does this need to connect to and do I need to buy special equipment or is it already in the truck and just need to be connected?

1,200 miles on her and still loving every minute!! :ro)

Do a search for Brake Controler.

There are several threads with model options and how-to.

Good Luck with your project.

Idahofox

Yes, you will need to get a brake controller for the trailers electric brakes.

Quick recommendation is the Prodigy by Tekonsha. They also have a Plug and Play harness for our trucks.