fischnrod - 2/2/2011 8:01 PM Is the trailer wiring diagram you posted on an earlier thread by deepwater a standard for all trailers?
http://www.tacklereviewer.com/uploads/trailerwiringdiagram.jpg[/QUOTE]</p>
Pretty much standard for any 4 way plug. </p>
If you have disc brakes on your trailer there is a 5th wire. Normally a blue one that activates a backup solenoid on your brake actuator. The plug connects to a plug on your truck that gets its 12volt feed when you put the truck in reverse. </p>
SOME harnesses do have a backup wire running full length down the trailer frame too. That's if they have installed courtesy backup lights. </p>