Troubleshooting Trailer Light Install For Jet Ski Trailer Being Towed By 1999 Jeep Grand Cherokee

Updated 03/23/2018 | Published 03/22/2018

Question:

Hi, I just bought an LED magnetic trailer light kit to upgrade my jet ski trailer and hopefully never have to replace them again as I can remove them before submersing the trailer. How do I wire the 4 pin trailer lead to my 1999 Jeep Grand Cherokee that has 5 wires running to each tail light? running, brake, reverse, signal, ground. I’ve attached the car’s ground wire to the trailer’s white wire, the running lights to the brown wire, left brake to the yellow wire and right brake to the green wire. This leaves me without turn signals on the trailer? I’ve thought of buying another set to use only as turn signals, but there has to be a way to wire one set so that the trailer has the full functionality of the car’s lights.

asked by: John

Expert Reply:

You may have already done this, but I would make sure you are connecting the 4-Way connector function to function and not necessarily color to color. You can use a circuit tester, Item # PTW2993, to confirm functions and proper connections. Regardless of color, you will need to connect:

Trailer's right turn signal to vehicle's right turn signal (probably green)
Trailer's left turn signal to vehicle's left turn signal (probably yellow)
Trailer's taillights to vehicle's taillights (probably brown)
Trailer ground to clean metal surface as separate wire from vehicle's ground (probably white)

If you are still having problems after connecting function to function, make sure connectors free of any damage, corrosion, or debris. After that, make sure strong grounds for vehicle and trailer. Next, check all wires to make sure nothing loose, pinched, or damaged. Finally, check fuses to make sure installed and functioning.

If you are still having challenges after these steps, contact us and we will look at other troubleshooting options.

To help with your installation, I am including some articles on wiring.