2014 Jeep Wrangler Left Side Lights Not Working when Connected to a Motorhome

Question:

Hi, I ordered a complete Roadmaster kit sorry forgot what its called that included the 7 wire 4 diode wiring for a 2014 jeep wrangler. It also included coiled safety cables, breakaway, etc. My problem is the wiring kit. I had a local shop wire it including the diodes in the rear tail light housing on each side. I plugged it in to my 2018 Class A Forest River Georgtown XL motorhome and the left drivers side jeep lights dont work Brake, tail, signal. Zero works on that side. The right side works fine Jeep tail, brake, signal. I took it back to the shop and they said the entire circuit tests okay. They connected the 7 wired coiled setup, powered it from the motorhome side of the circuit and all the rear lights on the jeep function as they should. Help? Could it be the motorhome plug is wired differently? I doubt thats it because I have connected and towed a trailer with it and the 7 plug worked fine. Thanks

asked by: Joe H

Expert Reply:

If everything works when the 2014 Jeep Wrangler is connected to a different 7-Way trailer connector, then that would indicate that the issue is more likely on the RV side. First you can test the RV's 7-Way using a circuit tester such as # PTW2993 or a meter if you have one. The pin on the RV's connector for the left turn signal and brake light is located in the 9 o'clock position. The running light circuit is shared.

If you are not getting any power on the pin in the 9 o'clock position when the brake pedal is pressed or when the left turn signal is on then the issue is somewhere in the RV's tow package wiring, the connector itself, or there is a fuse or relay that needs to be replaced.

If that pin does have power, then make sure you have the connector at the front of the Jeep grounded to a clean, bare metal surface. The white wire in the tow bar wiring you have is the ground. Assuming that it is connected to that connector at the front of the Jeep you may need to attach a second ground wire in the same place and run it to the vehicle chassis.

expert reply by: Michael H