Troubleshooting a Left Trailer Turn Signal That Blinks when Right Blinker is Applied
Updated 05/30/2026 | Published 05/30/2014 >
Question:
I have a 8 / 4 trailer and I get a right signal and brake, but when I pit it to left turn I get another right signal. Here is what I did. Brown wires to both lights yellow to left and green to the right and grounded white to trailer frame. What did I do wrong
asked by: Randy
Helpful Expert Reply:
Sounds like you wired both your left and right turn signals to your right turn signal. To correct this you will need to rewire your trailer. Since trailer wire colors can vary (not usually) you will make sure you wire by function and not just color.
The brown wire from the 4-way on your trailer is the running lights circuit and will need to be run to the running light circuit of both assemblies. This will be the lower illumination circuit. Typically the wire color would also be brown.
The green wire of your 4-way is the right turn/stop signal and will need to run to the right taillight assembly's stop and turn circuit. The yellow wire is the left stop and turn circuit, it will need to be run to the left taillight assembly stop/turn circuit. The white wire of the 4-way will need to be ground to the trailer frame.
I attached an FAQ on trailer wiring that you should find informative as well.
Product Page this Question was Asked From
Curt T-Connector Vehicle Wiring Harness with 4-Pole Flat Trailer Connector
- Custom Fit Vehicle Wiring
- Trailer Hitch Wiring
- Vehicle End Connector
- Converter
- No Tow Package
- 4 Flat
- Plug and Lead
- Plug-In
- Visible
- CURT
more information >
Featured Help Information
Instructions
Miscellaneous Media
Continue Researching
- Search Results: tr20117
- Shop: Trailer Wiring
- Shop: Weigh Safe Hitch w/ Built-In Scale for 2" Hitch, 8" Drop/9" Rise, 12.5K, Cerakote
- Shop: Weigh Safe Hitch w/ Built-In Scale for 2" Hitch - 8" Drop/9" Rise - 15K - Steel
- Shop: Weigh Safe Hitch w/ Built-In Scale for 2" Hitch - 4" Drop/5" Rise - 12.5K - Aluminum
- Video: Review of Weigh Safe Built In Scale Hitch 2 Stainless Steel Balls 2 Inch Receiver - WS66ZR
- Shop: Universal Installation Kit for Trailer Brake Controller - 7-Way RV and 4-Way Flat - 10 Gauge Wires
- Shop: Weigh Safe Hitch w/ Built-In Scale for 2" Hitch - 6" Drop/7" Rise - 15K - Steel
- Q&A: Recommended Hitch for a 2024 Subaru Outback Wilderness
- Shop: Curt T-Connector Vehicle Wiring Harness with 4-Pole Flat Trailer Connector
- Video: Review of Weigh Safe 2 inch shank Steel With built in Scale - WS48RR
- Q&A: Solution to Both Turn Signals Flashing at the Same Time w/ the 7-Way RV Upgrade Kit ETBC7
- Q&A: Finding The Cold Side Of The Brake Light Switch On A 2024 Subaru Outback Wilderness
- Shop: Weigh Safe Hitch w/ Built-In Scale for 2" Hitch, 6" Drop/7" Rise, 12.5K, Aluminum
- Article: Troubleshooting 4 and 5-Way Wiring Installations
- Video: Curt T-Connector Vehicle Wiring Harness with 4-Pole Flat Trailer Connector-C44ER Spec Review
- Q&A: Does Black Power Wire Of Curt T-Connector C44ER For 2021 Nissan Rouge Have To Be Run To The Battery?
- Q&A: Ways to Identify The Correct Brake Switch Wire For Trailer Brake Controller on 2024 Subaru Outback
- Q&A: Why Would Right Turn Signal Come on When Left Turn Signal is On for Trailer Wiring
- Q&A: I Installed the Curt T-Connector Vehicle Wiring Harness # C56403 & Trailer Left Taillight Stays On
- Article: Trailer Wiring Diagrams
- Search Results: trailer hitch
- Article: Brake Controller 7- and 4-Way Installation Kit (ETBC7)
- Shop: Trailer Hitch
- Search Results: trailer wiring
- Video: How to Choose a Trailer Brake Controller
- Search Results: trailer tires and wheels
- Shop: Suspension Enhancement
- Video: Curt T-Connector Vehicle Wiring Harness Review C56040
- Article: How to Measure for Trailer Hitch Drop




Jim S.
7/19/2020
No brake lights on trailer and left turn works signal works fine but when right turn is Activates. left turn on trailer comes on.Got the wrong one the first time , and this one isn't working from you guys I'm at $130 so far and frustrated.