How to Troubleshoot OEM 7 Way Trailer Wiring on Jeep Grand Cherokee

Updated 01/20/2020 | Published 01/18/2020

Products Featured in This Question

T-One Vehicle Wiring Harness with 4-Pole Flat Trailer Connector

(204)

$60.91

Hook Probe Circuit Tester

(60)

$12.41

Question:

I installed a OEM Jeep Grand Cherokee 7 PIN Trailer Wiring Harness Mopar. as per directions. I have no power to the pins, I checked all fusses and relays to the unit. Im at a stand still dont know what to don next. Thanks for your help.

asked by: Jess A

Expert Reply:

I'm sorry to hear that your having issues with your trailer wiring, but I am more than happy to help track down the issue. Since you checked the relays and fuses and I assume they are all good, there is something else going on.

I recommend that you do a basic run through of all the connections, and make sure they are solid, check the fuses and relays again. You can use a tester like # PTW2993 to run through all the functions and check each pin at the connector. If you are still not getting any kind of signal, power or light functions taking it to the dealer may be the best bet.

What I have seen with Jeeps and other Mopar products is that if the vehicle did not come from the factory with a hitch, or trailer wiring, even if you install the components later they will not power on. This is resolved by taking your Jeep to the dealer where they can hook it up to a scan tool and flash the Jeep's computer to "turn on" the circuits.

expert reply by: Robert C