Tail Light Wiring Functions on a 1985 Jeep CJ-7 to Install Diodes to Flat Tow Behind Motorhome

Updated 08/03/2018 | Published 08/02/2018

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Tail Light Isolating Diodes (Qty 4)

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Hook Probe Circuit Tester

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Question:

I have a 48955 diode kit but jeep has 5 wire to 3 wire plugs right before taillight Where do I tie in diodes

asked by: Pete

Expert Reply:

You will need to test the wires on your 1985 Jeep CJ-7 to determine the functions so you can install diode kit # 48955. To do this you can use a circuit tester such as # PTW2993 or a meter if you have one.

There should be one wire that is combined left turn signal and brake light. Another that is combined right turn and stop light. And there is a running light only wire behind each taillight. It is hard to say with any certainty which color wires do each of these functions which is why testing is required.

But I happen to have an old Jeep manual for the CJs 1984 to 1986, and it looks like the light green wires behind each taillight are the turn signal/brake lights while the all-white wires are the running light wires. There should be another wire that is white with a stripe that is apparently the ground.

expert reply by: Michael H