Looking For Load Resistors For Ford Truck Towing Trailer With LED Lighting

Updated 11/14/2026 | Published 11/13/2026

Question:

Our Boy Scout troop just bought a used Thule box trailer with all LED lighting. It works fine for all the vehicles except the FORDS. The running lights dont work with the FORDS/ We think it is because the LEDs dont draw enough current to wake up the trailer module. We have tested with multimeters, etc... There has to be some kind of resistor to wire into the brown wire, please help.

asked by: James A

Expert Reply:

Hey James, thanks for reaching out! This is a pretty common issue with Ford trucks and trailers equipped with LED lights, and you're on the right track looking for a load resistor. Some Ford trailer lighting modules have trouble detecting the low power draw of LED lights, which can prevent the running lights from working properly.

For this, I recommend the Load Resistor Kit # DI34ZR, which includes two 50-watt, 6-ohm resistors. These add electrical resistance to create an additional load on the circuit, helping the truck recognize the trailer's LED lights. Just make sure the resistors are wired in parallel with the running light circuit and mounted to a metal surface, since they generate heat during operation.

What kind of camping trips or adventures does your Boy Scout troop have planned with the trailer?

expert reply by: Jesse M

Load Resistor Kit for LED Turn Signals - 50 Watts - 6 Ohm - Qty 2
(click to enlarge)

James A.

11/13/2026

Thank you Jesse! Just ordered the resistor kit! This weekend we are going to Gettysburg. We do a lot of camping in Pennsylvania and NJ. Our old trailer was a wiring nightmare, then a tree fell on it… I was so excited to have a maintenance free trailer then this problem cropped up. Guess the ford guys won’t be laughing at my Volvo for a while. On that note, the stealth hitch you sold me went on great and is awesome!

Jesse M.

11/13/2026

@JamesA Nice! Yea that is typical Ford - if it ain't one thing it's another. Personally, I will never buy another Ford. About 10 years ago we got my wife a brand-new Ford Focus and it was basically lemon and the dealership stood us up. Anyway, glad I was able to help, and happy travels! You know where to find me if you ever need anything else!

Curt D.

11/14/2026

if you have a 2025 Ford it could have the same production problem mine did. I kept my old truck (a 2001 Ram). Our new trailer had LED lights running lights that worked as they should with the old truck. When plugged into the Ford, they didn't. I tried the load resistor but it didn't help. I took it back to the dealer, multiple times, for the same issue. Ultimately the problem was in a wire splice near the left rear fender that was not properly secured. Once that splice was repaired everything worked as it should. I actually drove home from a campsite to switch trucks because I knew I wouldn't have running lights, all due to a bad connection in a factory splice.