Why Would Curt Trailer Wiring for 2017 Kia Sorento Keep One Taillight Lit All the Time
Updated 08/04/2025 | Published 06/30/2023 >
Question:
I bought this harness for my 2017 Kia Sorento w/o towing package. The harness worked great for the first year I had it. But then I started having problems with my drivers side brake light on my trailer. Whenever the trailer was attached to the vehicle the drivers side brake light would stay on. The light still functions brake,turn,and running. But the light is always on. I have verified that all ground wires are firmly attached and grounded. Is there anything I can do to fix thus issue?
asked by: Christopher T
Expert Reply:
What you are describing sounds like an internally shorted converter box. Anytime we see a trailer taillight want to stay on and the connections are solid that indicates that a short in the trailer wiring most likely damaged the box and is preventing it from functioning properly. This is what the boxes are designed to do as they essentially are designed to fail in the event of a short to prevent it from making it's way to the vehicle wiring. Only solution is to replace the wiring kit.

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
- Powered Converter
- No Tow Package
- 4 Flat
- Plug and Lead
- Plug-In
- Hidden
- CURT
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Michael
8/2/2025
I have the same problem, the unit was installed by my car mechanic and seems like a easy installation, it worked on and off, so is it possible a grounding wire could also be the problem and if this unit was bad in the first place how do I get it replaced under warranty, or am I screwd??
Jameson C.
8/4/2025