Installation of Reverse Light Circuit on Trailer with 2013 Jeep Grand Cherokee with 4-way Connector

Question:

I have a 2013 Jeep Grand Cherokee without factory tow package. I found the 2013 Jeep Grand Cherokee T-One Vehicle Wiring Harness with 4-Pole Flat Trailer Connector that should help me with the pick-up of the lights signals for the boat´s plug. My question is regarding the other accesory that I need to go from the 4-flat to the 7-pin round connector that fits to my boats trailer. This trailer has backup lights and separate navigation and brake lights and I don´t know if there is a straight adaptor from the 4-flat to my 7-pin round on the boats trailer. Thank you very much!

asked by: Felix H

Expert Reply:

It sounds like you need the # 37185 wiring harness. This connector will adapt your 4-way wiring to a 7-way connection and the purple wire will connect to your reverse light connection on your vehicle to transmit the signal onto your trailer. You will need some 10 gauge wire to splice in this connection # DW02359-1 and # SWC502905-1. For any unused wires you will want to cap them off or secure them with electrical tape and zip tie them out of the way.

Have a helper place the transmission in reverse, while you use a circuit tester like part # PTW2993 on the wires leading to the reverse light bulb. When you find the circuit that goes hot only when the transmission goes into reverse, that's your reverse lamp circuit.

If your trailer has brakes for which you also need a connection, I recommend the # ETBC7 which includes the # 37185 and all the parts needed to make these connections for a brake controller.

It also sounds like your trailer was equipped with a converter like # 118158 which allows for the wiring signal to be adapted for separate lights on your trailer.

I have linked several Help Articles and pictures for you to better see how this connection will be made.