Troubleshooting Trailer Wiring Not Working With Blown Truck Trailer Wiring Fuses
Updated 01/12/2026 | Published 09/03/2024
Question:
The left light does not work light has no running light only, no brake light, or turn signal while on the right side is fine to turn light night light brake light on the Travel Trailer and found to blow 20 amp on the tow trailer and fine a few miles like 20 or 30 miles blew up again left no light ... so could need the replacement on the inside connector my truck is brand new 2022 Ram so disconnect my travel trailer and reconnect on enclosed trailer so same problem a connector is 7 ways and 4 ways
asked by: Christopher J
Expert Reply:
Hey Christopher, so one of two thing is going on most likely. Since fuses are blowing on your trailer wiring circuits that indicates to me that you have a short to the trailer frame on the wiring for the lights. So what you'll need to do is go over the wiring of the trailer looking for any exposed wire and fix as needed. It's probably touching the trailer frame and over time has rubbed through the wire's insulation.
The other less likely option is that the ground wire of the lights isn't attached anymore so check for that and fix as needed.
Product Page this Question was Asked From
20 Ft 4-Way Trailer Wiring Harness - Wishbone Style - 30" Ground
- Trailer Wiring
- Trailer Connectors
- Trailer End Connector
- 4 Flat
- Plug and Lead
- Optronics
more information >
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Jameson C.
1/12/2026
Hey Christopher, did checking the trailer wiring and ground connection fix the issue with the left light blowing the fuse? Knowing what you found could help others chasing the same short on their trailer.