Receiving No Power at Didoes on 1985 Jeep CJ-7 from the RV 4-Way Trailer Connector

Question:

I am trying to wire my CJ-7 lights for towing with my 1999 Fleetwood Vision motorhome. The RV has a 4-wire round connector. I have installed diodes to isolate the jeep wiring from the RV wiring. The brake, turn signal, and clearance lights work correctly from the jeep wiring, but I dont get any voltage through the diodes when I use the RV. I have 12 VDC at the diode from both the jeep and the RV. Is this a grounding issue?

asked by: Bob A

Expert Reply:

The 1985 Jeep CJ-7, has combined brake lights and turn signals so you would need to wire it with diodes according to the FAQ I have linked for you.

If you check the diagram, you can compare it to how the installation is on your Jeep. You should have 4 diodes. The wires that connect from the plug at the front of the Jeep and lead back to the diodes should be grounded. The 4-Way white wire will need to be grounded to the vehicle frame. It will need to be attached to a clean and corrosion free bare metal surface. A bad ground could cause the problem.

However, the 4-Way round connector can be tricky because there is no set way to wire them. You may be in a situation where the configuration on the RV is different than the configuration on the wiring harness that connects the RV and the Jeep.

Check the ground and the trailer connector configurations. Use a circuit tester like # 3808 if needed. If the configurations do not match you may need to adjust the trailer side connector to match everything else. I have included a link to a video that also may help you.

expert reply by: Michael H