Vehicle Blows Fuse When Trailer is Attached
Question:
I have 1993 GMC 3500 that i picked up used about a year ago, the truck has aftermarket trailer plug in on it. When i plug my trailer into it it blow the fuse in the truck. I can plug this same trailer into my 2006 2500 with no issues lights work fine and no fuses blown. So this leads me to believe that the problem is with the truck and I have chased wires cleaned the connectors checked ground and nothing. Any ideas ?
asked by: Ernie A
Expert Reply:
I would agree that the problem appears to be on the vehicle side. Generally speaking, most of the time when a vehicle's fuse blows as a result from attaching a trailer, the cause is usually attributed to either the trailers lights exceeding the vehicle's trailer lighting circuit or there is a short somewhere along the wiring harness. If you have previously pulled the trailer with the vehicle in the past, then I would lean towards a wiring issue but if you have never pulled this trailer before with the vehicle then my assumption is that the vehicles trailer wiring circuit is not capable of handling the amperage of the trailer's lights.
If you have pulled this trailer with your truck in the past, then I would re-check the wires with a circuit tester like part # PTW2993. In order to do this, you will need to activate the vehicle's lights while testing the corresponding wires just before the vehicles trailer connector (with trailer unhooked). If one of the wires does not illuminate the test light and it should, I would trace that wire as far back as possible paying close attention for breaks or frays. Use electrical tape to close any potential weak or loose connections on the wire.
If you have not attached the truck and trailer together before then one could only be led to believe that the trailer's lighting circuit is exceeding the vehicle's trailer lighting circuits capacity. In order to fix this, I recommend installed the Upgraded Heavy Duty ModuLite Circuit Protected Vehicle Wiring Harness with 4 Pole Trailer Connector part # C59496. The powered coverter box included in this kit will draw its power from the vehicle's battery and distribute the correct amount to each lighting circuit on the trailer. If you have a 7-way trailer connector at the rear of the vehicle you could then use the Adapter 4-Pole to 7-Pole and 4-Pole part # 37185.
Let me know if either of these options provide a solution for you.
![Conner L](https://images.etrailer.com/static/images/catg/people/1234_tn.jpg)
Products Referenced in This Question
Adapter 4-Pole to 7-Pole and 4-Pole
- Trailer Wiring
- Wiring Adapters
- Multi-Function Adapter
- 4 Flat
- Plug and Lead
- 4 Flat
- 7 Round - Blade
- Hopkins
more information >
Curt Powered Tail Light Converter w/ 4-Way Flat Trailer Connector and Install Kit
- Custom Fit Vehicle Wiring
- Trailer Hitch Wiring
- Converter
- 8 Feet Long
- Universal Fit
- 4 Flat
- CURT
more information >
Product Page this Question was Asked From
Featured Help Information
Instructions
Miscellaneous Media
Continue Researching
- Article: Trailer Wiring Diagrams
- Article: Wiring Trailer Lights with a 7-Way Plug (It's Easier Than You Think)
- Article: Brake Controller 7- and 4-Way Installation Kit (ETBC7)
- Article: How to Troubleshoot Your RV Air Conditioner
- Article: Brake Controller Installation: Starting from Scratch
- Article: Testing Trailer Brake Magnets for Proper Function
- Article: Troubleshooting 4 and 5-Way Wiring Installations
- Q&A: Will The Curt Dinghy Wire Harness # C96JR Interfere With Activation Of A Blue Ox Patriot
- Q&A: How to Make an Adapter to Go from Semi Truck 7-Way Round to RV Style 7-Way Blade on Trailer
- Q&A: How to Test Brake Controller without Trailer Connected
- Q&A: Wiring Needed For Operating Tail Lights On a 2023 Jeep Wrangler When Flat Towed Behind a Motorhome
- Q&A: Can the Curt Custom Tail Light Wiring Kit Be Used With LED Lights
- Q&A: How to Install a Brake Controller on a 2007 Ford F-150
- Q&A: Trailer Plug is a 4-Way Flat But there are 6 Wires