How to Determine Which Wires Need to be Connected to Which Pins on a Trailer Side 7-Way

Question:

Hello. I have the same wire colors as is described in the wiring diagram for a 7 pin trailer plug connector except for the purple. I have a red instead of the purple. This is the plug from the truck. Ive tried putting the red in the center to no avail. Any recommendations?

asked by: Chuck P

Expert Reply:

Since there is no universally accepted wiring color it is always best to test the wire functions on a trailer by using a 12V battery to determine what function each wire performs. If you check out the attached picture you can see that there is no purple-colored wire in this diagram.

Once you find out what the different functions are, you can then correctly wire your trailer side 7-Way connector, like part # PK12706, using the picture. This should match up directly with the functions on the 7-Way of your tow vehicle. You can verify this as well by using a Circuit Tester # PTW2993 to test the various functions of your tow vehicle 7-Way.

expert reply by: Jon G