Troubleshooting Trailer Wiring Where No Lights Work
Updated 09/30/2025 | Published 09/24/2025
Question:
Hi, I just bought the Curt T-Connector Vehicle Wiring Harness with 4-Pole Flat Trailer Connector C56327 for our 2024 Ford transit 150. I installed it, the tail lights were working, but when we plugged in the trailer, the trailer lights did not work. We got another harness thinking it was that, but still the same issue. I have it wired to the battery under the driver seat, could that be the reason the lights arent working? Or could it be something else? Thank you
asked by: Matthew F
Expert Reply:
Hey Matthew, are you sure the problem isn't the trailer taillights? Do you have a circuit tester that you could test the pins of the 4-way with to see if you can find out if the problem is for sure on the vehicle or trailer side?
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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Matthew F.
9/25/2025
Hi, It is not the trailer. The trailer works with my other trucks. I have bought other harness for our Mavericks and they work fine with this trailer. Not sure what it could be.