Troubleshooting 5-Way Trailer Connection on 1986 Jeep Grand Wagoneer

Question:

I would like to use the OEM wiring harness that is at the back of the vehicle. It is a flat 5 plug, but is quite a bit longer than the flat 5 trailer plugs that I’m finding at the auto parts stores. The pins are spread out more on my Jeep and don’t line up with the flat 5 plug that I bought. Any solutions? Is there a converter or something? Have the flat 5 plugs changed since 1986? Thanks for your help. I’ve looked all over the net and can’t find any solutions.

asked by: Michael C

Expert Reply:

A 5-way is not normally an OEM option on vehicles, so there is a very good chance it is not an OEM part. With the pins spread out more, that makes it even less likely to be an OEM 5-way as the plugs have not changed shape or width since 1986.

I recommend using a circuit tester like # PTW2993 to check the wiring functions. I've attached a video to assist. The 5th function will either be reverse light function that will only come on when the vehicle is shifted into reverse, or a brake controller output which will only have power when you hit the manual override. I've attached an article to assist.

To keep the length, you desire if the functions are correct, I recommend using # HM47900 to give you the connector compatible with traditional 5-way trailer connectors like # HM47910. I recommend the Deka Heat Shrink Butt Connector - 16-14 Gauge - Nylon Insulation - Blue - Qty 5 # DW05744-5 to ensure a good connection that will keep moisture and debris out.

expert reply by: Jason S