Troubleshooting License Plate Lights Not Working For Brand New Trailer
Question:
License plate lights went out on brand new tailer. All the other lights on trailer work fine. Changed out the bulb and still isn’t working. What else could be the issue?
asked by: Ramiro N
Expert Reply:
You may have a short in the wiring or the ground is bad for your license plate lights. You can use a Test Light # PTW2993 to determine if you have power getting all the way to the light socket. This is generally the prong on the bottom of the bulb depending on what light bulb it uses. If not you will want to trace the power wire to determine where the wire is damaged and fix this.
If you have power getting to the light you will next want to check the ground. Corrosion can often build up between the frame and wiring causing the connection to fail. You can clean these surfaces, reattach the connection and verify if the lights begin to work.
Let me know if you are still having issues.

Product Page this Question was Asked From
Continue Researching
- Article: Trailer Wiring Diagrams
- Video: This Old Trailer: Troubleshooting the Ground Wire
- Q&A: Dimensions Of The Optronics 7-Pole Blade to 5-Pin Delphi Connector Strain Relief
- Shop: 7-Pole Blade to 5-Pin Delphi Connector Wired Trailer Adapter with 2-Pin Backup Camera Plug - Coiled
- Shop: Hopkins Custom Tail Light Wiring Kit for Towed Vehicles
- Q&A: Is the Optronics 7-Pole Blade to 5-Pin Delphi Connector Available W/ Out Backup Camera Plug
- Q&A: Correct Wiring for Optronics LED Trailer Lights # STL22RB
- Shop: Tekonsha Plug-In Wiring Adapter for Electric Brake Controllers - Ford
- Shop: Tekonsha Plug-In Wiring Adapter for Electric Brake Controllers - GM
- Shop: Roadmaster Smart Diodes for Variable Voltage LED Tail Lights - Qty 2
- Shop: Curt 2-to-3 Tail Light Converter for Towed Vehicles w/ Incandescent Tail Lights
- Shop: Universal Installation Kit for Trailer Brake Controller - 7-Way RV and 4-Way Flat - 10 Gauge Wires
- Q&A: Wiring Trailer for Two Batteries, Breakaway Battery and Auxiliary Battery
- Q&A: What is the Difference Between a Class II and a Class III Hitch?
- Video: Finding the Right Trailer Wiring Harness
- Search Results: trailer wiring
- Article: Wiring Trailer Lights with a 7-Way Plug (It's Easier Than You Think)
- Video: An In-Depth Look at the Roadmaster Diode 7-Wire to 6-Wire Flexo-Coil Wiring Kit
- Search Results: trailer lights
- Article: Brake Controller 7- and 4-Way Installation Kit (ETBC7)
- Q&A: Recommended Complete Flat Towing Setup for a 2024 Jeep Wrangler
- Video: An In-Depth Look at the Roadmaster Battery Charge Line Kit for Towed Vehicles
- Search Results: trailer hitch
- Shop: Trailer Hitch
- Article: Wiring Trailer Lights with a 4-Way Plug (It's Easier Than You Think)
- Video: Choosing the Right Tow Bar Wiring
- Search Results: base plate for tow bar
- Q&A: Instructions to Wire a Trailer for Electric Brakes
- Search Results: trailer breakaway kit
- Article: Trailer Lighting Requirements