Troubleshooting LED Clearance Lights On Semi Trailer Flashing Faintly When Using Turn Signals.
Updated 06/05/2023 | Published 06/02/2023 >
Products Featured in This Question
Question:
I have rewired a semi trailer with 14ga wire. I have installed all led lights throughout the trailer, and two ground wires. Only when the clearance and the running lights on all the lights will faintly blink when a right or left signal light is turned on. I also have a junction box installed and I have run a much larger jumper directly from the trucks negative on the battery cable and it still blinks.
asked by: Jon
Helpful Expert Reply:
It sounds like there may be an issue with power shorting into the clearance and running lights when you use the turn signals. As LED lights do not require a lot of power it may be the power is jumping the circuits inside your junction box. Be sure to also check for any signs of power shorting inside the trailer connector. Some Dielectric Grease # 11755 should help prevent an issue inside the trailer connector. If your power is shorting inside the junction box you can try some Liquid Electrical Tape # SWC50122 to cover the connectors.
Product Page this Question was Asked From
Dielectric Grease for Electrical Connectors, 2 oz.
- Accessories and Parts
- Trailer Wiring
- Wiring
- Dielectric Grease
- LubriMatic
more information >
Continue Researching
- Q&A: Wiring Needed To Tow a Trailer With Brakes With a 2025 Ford Ranger no Tow Package
- Q&A: Is There Tow Bar Lighting and Trailer Wiring Solution for 2015 Jeep Wrangler Sport S
- Q&A: Is Dielectric Grease Good For Protecting My 4-Pin Trailer Connector?
- Article: Brake Controller 7- and 4-Way Installation Kit (ETBC7)
- Q&A: Locking Hitch Pin For Swagman Bike Rack
- Q&A: What Bracket Goes With The TowSmart ProClass Trailer Connector TS59RR?
- Q&A: How to Clean a 7-Way Trailer Wiring Connector
- Article: Holiday 2025 | RVers’ Favorite Gear & Road Picks
- Q&A: Trailer Hitch and Wiring Recommendation for 2025 Hyundai Santa Fe
- Article: How to Measure Your Trailer Wheel Bolt Pattern
- Article: Trailer Wiring Diagrams
- Article: Wiring Trailer Lights with a 7-Way Plug (It's Easier Than You Think)
- Article: Adding Electric Over Hydraulic Disc Brakes
- Article: Gooseneck to 5th Wheel Adapters

