Troubleshooting Trailer Tail Lights Always On with Curt T-Connector Wiring Harness
Updated 06/26/2026 | Published 06/25/2021
Question:
Installed t connector on 2021 chev trax purchasedon 02/17/2021 tail lights on trailer are on all time even when car is shut down can probelm be in converter
asked by: William W
Expert Reply:
There are a few possible reasons why the trailer lights are on all the time on your trailer. The first possibility is that your trailer lights are LED. LED lights take significantly less power so it is possible to see a dim glow even when the vehicle is off. You can simply disconnect the trailer wire from your vehicle to put a stop to this.
If they are fully illuminated that may be a different problem. According to Curt, a malfunction in the converter on the # C43FR wiring harness would still not result in the lights remaining fully powered on when your vehicle is off. I would recommend checking the connections and the wiring, especially the in-line fuse holder and connection to the battery. The wiring harness also has a 1-year limited warranty, so you are within that period.
I have attached the review video below which runs through the installation steps for your reference.
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
- Hidden
- CURT
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Jean-françois R.
6/26/2026
Hi, I reconnected the engine ground, the fuse ground, and the ground in the vehicle frame. I sanded the connections before tightening the screws. The problem still persists—the trailer lights stay on all the time. The turn signals don't work. They just stay on and don't do anything else.