I need to hook up wiring to plug into a trailer on a 2007 Ford Fusion SE. Started hooking up wiring but for some reason when wiring it I can not get it to work. Do I need a special kind of plug to make it work? I have got the running light to work and both right and left signels to work. Brakes screw up blinkers.

The book I got of yours has no info about this. I have the hitch on the car now.
Help.