Trailer Lights are Dim When Connected to Truck
Updated 05/03/2017 | Published 05/01/2017 >
Question:
i have a 4 post plug on my tralior and truck with the test lite shows wired correctly but when i plug the them in the lites are dim and when you when you use the blinkers they both flash very dim and i cleaned the frame and made a new ground to the frame
asked by: Don D
Expert Reply:
Sounds like you have a ground issue on your trailer. Ground problems normally show up when there is more draw on a system such as when you have the running lights on and then use another function like a turn signal or brake light but can show up any time.
Locate the main trailer ground wire. Disconnect the wire and clean the surface that the wire is connected on your trailer. Make sure that the connection is on bare metal. No rust, paint, dirt, or grease on the trailer's surface where the ground will be attaching.
Also, make sure the vehicle side and the trailer side connectors are free of corrosion both inside and out.
Check the light grounds to make sure they are attached to a clean and corrosion free bare metal surface. If there is anything in between the light grounds and the metal trailer frame could interrupt the ground.
The attached diagram will show the what the general wiring for a trailer.
Product Page this Question was Asked From
35 Ft 4-Way Trailer Wiring Harness - Wishbone Style - 42" Ground
- Trailer Wiring
- Trailer Connectors
- Trailer End Connector
- 4 Flat
- Plug and Lead
- Optronics
more information >
Continue Researching
- Q&A: Possible Causes for Dim Trailer Lights
- Search Results: led adapter
- Shop: TecNiq Heavy Duty Bicolor Mini Fender Light - Red / Amber
- Shop: Trailer Wiring
- Video: Easily Install Your TecNiq Heavy Duty Bicolor Mini Fender Light
- Shop: Load Resistor Kit for LED Turn Signals - 50 Watts - 6 Ohm - Qty 2
- Shop: 7-Way Trailer Adapter for Towing Trailers with LED Lights
- Video: Review of TecNiq Trailer Lights - Clearance Lights - Reflectors - TN32TR
- Shop: LED Trailer Fender Light w/ Mounting Bracket - Waterproof - 2 Diodes - Amber/Red Lens
- Video: Peterson LED Identification Light Bar Review
- Search Results: primary wire
- Search Results: identification light bar
- Shop: Optronics LED Clearance or Side Marker Light - Submersible - 3 Diodes - Rectangle - Amber Lens
- Shop: Optronics LED Clearance or Side Marker Light w/ Reflex Reflector - 6 Diodes - Square - Amber Lens
- Shop: Peterson Mini Identification Trailer Light Bar - Incandescent - White Steel Base - Amber Lens
- Q&A: What is the Difference Between a 4-Way and 7-Way Trailer Connector
- Article: Wiring Trailer Lights with a 4-Way Plug (It's Easier Than You Think)
- Article: Trailer Wiring Diagrams
- Shop: Trailer Hitch
- Shop: Brake Controller
- Q&A: Troubleshooting Dim Function of Brake Light and Turn Signal on Travel Trailer
- Q&A: Trailer Lights are Dim Just on One Side of Trailer
- Q&A: Troubleshooting Dim Trailer Lights and Running Lights and Turn Signals Blinking Together
- Video: Installing the Buyers Trailer Wiring Junction Box
- Video: Redarc Tow-Pro Liberty Brake Controller Installation - 2022 Chevrolet Express Van
- Video: Let’s Check Out the Trailer Wiring Junction Box
- Video: Redarc Tow-Pro Liberty Brake Controller Review RED24FR
- Article: Troubleshooting 4 and 5-Way Wiring Installations
- Search Results: trailer brake controller
- Search Results: junction box


