Troubleshooting Lighting Issues When Hooking 2016 Ram 2500 Up To Trailer

Updated 12/15/2025 | Published 11/09/2024

Question:

I have a 2016 Ram 2500. I haven’t hooked up to a trailer in a bit but now when I do the brake lights and turn signals work. When I go to turn on all my lights on the truck, the trailer marker lights come on then go on and off a few times as well as my pickups license plate lights. I can’t figure out why this is happening, I’m stumped. I’m not good with wiring.

asked by: George B

Expert Reply:

Hello George, thanks for reaching out. The first thing to check here is the ground on your trailer and on your vehicle wiring harness. A bad ground can cause all kinds of random lighting issues which it basically exactly what you are describing. If you haven't pulled a trailer in a while it could be your ground corroded/rusted and is no longer good. Try using a new ring terminal and make sure you are grounded to good clean metal free of any paint, rust or corrosion. I suspect fixing the ground will resolve your issue. If it doesn't just let me know and I am happy to help you troubleshoot further.

expert reply by: Jesse M

Jesse M.

12/15/2025

Hey George, did cleaning up the ground connection on your Ram and trailer wiring clear up the flickering lights? Your update could make it easier for others running into the same issue.