Trailer Lights Not Working Using Optronics Trailer Light Kit # TL29BK On 1995 Mitsubishi Montero

Question:

I have a newly installed Peterson M545 trailer kit on a 95 Mitsubishi Montero with the Valley tow package from your site including Draw-Tite Upgraded Circuit Protected Taillight Converter Hardwire Kit with 4 Pole End. I installed both items according to your instructional videos. The Peterson kit 4 Pole end doesnt look like it matches up to the vehicle end. It does not have a separate brown wire for the running lights. Anyway, when I plug it in and test heres what happens. Hit the brakes all lights light up bright including side markers. Hit left turn signal, it lights up left side including side marker, same with right turn signal. Running lights do not work at all. Yet when you turn on the running lights, none of the turn or brake lights work. Ive tested the signals coming out of the vehicle side 4 pole and they all test out correctly. I havent checked the voltage from them. Any thoughts? Thanks.

asked by: Paul G

Expert Reply:

Since you have tested the vehicle side connector and they work correctly, you have eliminated the vehicle side as being the problem. So you will want to check the trailer wiring and the ground connections on the trailer.

The Peterson M545 trailer wiring kit you have mentioned uses a wishbone harness like the Optronics Standard Trailer Light Kit # TL29BK that we sell. This means it will have 5 wires coming out of the back of the 4-pole connector. That might be why it looks like it does not match the vehicle end connector. It will have a ground (white) wire, two running light wires (brown/yellow and brown/green), and a left turn (yellow) and right turn (green) wire. I am including a video link that will describe the wishbone harness and show how it is installed.

Make sure the white wire is connected to a good, clean ground on the trailer frame. The brown/yellow wire will connect to the left side taillight. The brown wire/yellow wire will go to the hole marked taillights, and the yellow wire will go to the hole marked stop and turn .

The brown/green wire will connect to the right side taillight. The brown/green will go to the hole marked taillights, and the green wire will go to the hole marked stop and turn.

The side marker lights should tap into the brown wire on each side.

The taillights are grounded through the mounting studs so you will want to make sure that the taillights have a good ground where they are bolted to the trailer frame.

expert reply by: Jeff D