How to Test to Determine Unknown Wire Color Functions of Trailer Wiring

Question:

Hello, I purchased an old RV and some one had removed the plug from the trailer. It has 9 Wires. My Truck has the Typical 7 blade connector. What and how do I correct this situation. The extra wires are orange and gray.

asked by: Carl J

Expert Reply:

Orange and gray are not standard trailer wiring colors so you'll need to do some testing to verify what those circuits carry. What you'll need to do is use a jumper wire from the positive pin of a 12 volt car battery to apply voltage to all of the wires to see which trailer circuits apply. The one that sparks when the connection is touched is the ground.

For a new 7-way though we have the # H20046 which I attached a chart that shows how this gets wired as well by color.

expert reply by: Jameson C