Troubleshooting Curt C56020 Not Working Correctly On 2006 Ford E350 Passenger Van
Updated 09/02/2025 | Published 08/09/2025
Question:
To whom concern, I brought a trailer wire harness from you all for my 2006 Ford E350 super duty passenger van and when I hook trailer wire to van the brake lights and trailer lights goes out but when I unhook trailer connectors on passenger side of van trailer lights comes on
asked by: Armstead R
Expert Reply:
Hello Armstead, thanks for reaching out. It sounds like the plugs/connectors on the Curt # C56020 wiring harness are not seated all the way. This is actually kind of common with these harnesses and it would explain why the lights are working that way. Try unplugging both sides and plugging them back in firmly to see if the problem goes away. Make sure the vehicles connectors are not bent or rusted. This wiring harness does not have a converter module so there really aren't any other troubleshooting steps for these. If its plugged in it should work.
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
- No Converter
- No Tow Package
- 4 Flat
- Plug and Lead
- Plug-In
- Hidden
- CURT
more information >
Featured Help Information
Instructions
Continue Researching
- Shop: Trailer Wiring
- Shop: Curt T-Connector Vehicle Wiring Harness with 4-Pole Flat Trailer Connector
- Article: Brake Controller 7- and 4-Way Installation Kit (ETBC7)
- Q&A: Brake Controller Wiring Harness and Air Bags for 2014 E-450
- Q&A: How to Use a Curt Echo Wireless Brake Controller on a Vehicle w/a 4-Way Connector
- Q&A: Parts Needed To Add 7-Way Connector To 2011 Ford E-350 Without Factory Towing Package
- Article: Brake Controller Installation on a Ford Full-Size Van
- Q&A: Parts Needed To Add 7-Way Trailer Wiring And Brake Controller To 2014 Ford F350 Van
- Q&A: What Do I Need to Install a Brake Controller on My 2013 Ford E-350 Without Factory Connector
- Q&A: Installing a Brake Controller on a 2014 Ford E-350 Van
- Article: Brake Controller Installation: Starting from Scratch
- Q&A: Parts Needed to Add 4-Way and 7-Way to 2013 Ford E350
- Article: Wiring Trailer Lights with a 7-Way Plug (It's Easier Than You Think)
- Article: Wiring Trailer Lights with a 4-Way Plug (It's Easier Than You Think)
- Article: What Do I Need To Tow A Trailer?
- Article: Towing a Trailer? Let's Talk About Brake Controllers
Jesse M.
9/2/2025
Hey Armstead, did re-seating the connectors on your wiring harness solve the issue with the brake and trailer lights? I'm asking because your experience could help others who might face a similar problem.