Wiring Aftermarket 7-Way Vehicle Side Connector to 2008 Ford F-150 Factory Tow Wiring

Question:

I had to cut end off of factory wiring harness because the 2 ends was not a match so I had to cut end off of the new plug also.I am trying to straight wire it back but the wires are not the same color and I cant seem to get it right.Factory harness wires are color Orange,Yellow, White,Blue,Green,Black with small reddish streak, Brown with whitish streak. Wires from back of new plug on bumper are color Purple,yellow,green, brown, black,white,blue.

asked by: Mccoy W

Helpful Expert Reply:

I can certainly help you determine the functions of the colors on the replacement 7-Way trailer connector, since the wire colors used are industry standard. For the replacement 7-Way, the purple wire is for the reverse light, the yellow wire is the left turn/stop, the green wire is right turn/stop, the brown wire is the trailer taillights, the black wire is the 12V lead, the white wire is the ground, and the blue wire is the brake signal.

You will want to use a circuit tester, like # PTW2993, to determine the functions of the vehicle's factory tow wiring. Since vehicle manufacturers can use different color wiring for tow packages, or other wiring, even within the same model year, the best way to know the functions of the wires is to test them. It is easiest if you have a helper who can sit in the truck cab and work the lights and signals, while you test each wire to determine the function. I have attached a review video of this circuit tester for you.

You can use butt connectors to make the connections between the vehicle wiring and 7-Way connector. I recommend using heat shrink connectors, like # DW05744-5 for 16 guage and # DW05745-5 for 12 guage wire, because they will help provide a better connection than standard butt connectors.

I have attached a help article on trailer wiring that hopefully will offer some insight for you as well.

expert reply by: Victoria B