Why is My Number 10 Fuse Blowing When I Hook My Trailer Up to My 2006 Ford Van?
Updated 06/06/2026 | Published 04/17/2025
Question:
When I plug my C56020 into a trailer or my 7 way adapter, my number 10 fuse pops and I no longer have running lights. I have tested extensively and believe my C56020 is defective. I have read other reviews of people having the same problem.
asked by: Bry T
Expert Reply:
Hi Bry,
It looks like the issue might not be with the brake controller after all, but possibly with the wiring.
If your #10 fuse keeps blowing when you hook up your trailer to the CURT # C56020 T-Connector on your 2006 Ford van, it’s likely due to a short somewhere in the trailer’s wiring, especially in the running lights, which that fuse typically protects. Common culprits include pinched wires, corroded sockets, bad bulbs or LEDs, or a poor ground. Occasionally, the trailer plug might be miswired, or in rare cases, the CURT harness itself could be faulty or damaged.
A simple test: unplug the trailer and see if the fuse still blows. If it doesn’t, the problem is definitely on the trailer side. I recommend double-checking all wiring, especially near the lights and where it contacts the frame. Make sure all ground connections are solid. If you have a multimeter or trailer light tester, those can really help narrow it down.
I’d hate for you to go through a warranty return on the wiring harness only to hook up the new one and run into the same issue. Once you’ve checked the trailer wiring and bulbs, let me know if everything looks good, I’ll get you the warranty info.
Also, do you have another vehicle you can hook the trailer up to? That could be a quick way to confirm where the problem lies.
Let me know how it goes!
Bry
6/6/2026
It took me forever to figure out that this harness was wired wrong from the curt factory. The ground wire was looped incorrectly and caused the fuse to blow. The same thing was wrong with the replacement I got. After banging my head against the wall trying to find anything wrong with my van, I looked at reviews on Amazon describing the same problem. I soldered the wires correctly and the problem was fixed. I tried curt customer service and they just had me check continuity on each wire. I wasted a ton of time and effort to get this simple harness to 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 >
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Bry T.
4/17/2025
I have confirmed it is not the trailer. Connected another trailer and the fuse popped with that one too. I would like to make a warranty claim for the C56020