Troubleshooting Install of Curt Trailer Wiring Harness # C63DQ
Updated 07/06/2026 | Published 06/08/2026
Question:
i installed Curt T-Connector Vehicle Wiring Harness with 4-Pole Flat Trailer Connector C63DQ on my VW, everything seems correct on my part but when i went to plug in the trailer lights the left turn indicator would turn blink both lights and the right turn would not let any lights blink. The light worked correctly on my truck so i know they are not the problem. any help would be great! thank you
asked by: corey r
Expert Reply:
Hey Corey, has the trailer had any recent rewiring done on it? It sounds like some of the circuits may have gotten swapped around and now the left turn signal is actually flashing the running light circuit and if you check the wiring and address that issue you should be good.
Natalie B.
7/1/2026
I recently installed the same kit in my car (2021 VW Jetta SE) and had the exact same issue. Left does both, right does nothing. The white on the 4 flat does read as ground. I also found a forum elsewhere where the same issue was mentioned
Jameson C.
7/1/2026
Jameson C.
7/1/2026
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
more information >
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Corey R.
6/8/2026
I did not rewire the trailer. the lights are for a bike rack on the back of the VW. They came ready to plug in, and they do work on my ford f250 properly. I thought it could be a grounding issue but it did no seem to be the problem. I took a meter to the 4pin plug out and only got a reading on the white cable, and no reading on the rest of the pins when i had someone use the turn signal or brakes. Do you think the computer module is bad?