Troubleshooting the Curt T-Connector Vehicle Wiring Harness Running Lights Not Working
Updated 09/02/2025 | Published 06/30/2025
Question:
Hello, I just finished installing the wiring harness on my 2022 Corolla cross le. The trailer is brand new and the lights worked when I tested it with my parents pick up. Now when I plug it into my Corolla, the brake and blinkers work but no running lights work. The fuse that came with the kit looks ok. I’m having a tough time figuring out what it could be. Any suggestions are appreciated. Thank you.
asked by: Bridger B
Expert Reply:
Hey Bridger, welcome back. So long as you have LED lights you have the correct part for your 2022 Toyota Corolla Cross. I recommend checking the ground on your Curt T-Connector Vehicle Wiring Harness item # C39DR. It should be firmly attached to a bare piece of metal with no paint beneath the ring terminal.
What kind of trailer are you pulling?
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
- Visible
- CURT
more information >
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Jerred H.
9/2/2025
Hey Bridger, did checking the ground on your wiring harness help resolve the issue with your running lights? I'm eager to hear about your experience, as it might help others facing similar challenges with their trailers.