No Power on 7-Way 12V Pin After Batteries Replaced
Question:
The interior lights on my trailer quit working after I changed the batteries in my 2012 f350 diesel truck. The A pin in the 7 pin does not have voltage. any thoughts? Is there an activate sequence for that circuit?
asked by: Eddy A
Expert Reply:
There isn't an activate sequence like what's seen in the later model Ford trucks with the 'smart' trailer connectors.
What Ford refers to as the 'Trailer Tow Battery Charge' circuit is protected by a 25A fuse in location # 90 in the power distribution box in the engine compartment. Most likely a short occurred in that circuit that caused the fuse to pop.
Check the trailer connector at the rear of the vehicle, make sure it isn't damaged or corroded. If you can see white or green corrosion on the pins, it's possible that the corrosion has spread to the interior of the connector and allowed two of the internal terminals to bridge, causing a short. Clean/repair/replace as needed.
Next, trace the 12-volt circuit on the trailer. Look for pinched wires or loose connections or cracked/worn wire insulation-anything that would allow the wire to short out to the trailer frame. Once the short is located and repaired, you should be good to go but you will want to find and fix it, otherwise you'll continue to blow fuses.
Product Page this Question was Asked From
Curt 7-Way to RV Socket LED Circuit Tester - Vehicle End
- Electrical Tools
- Testers
- Circuit Tester
- Tow Function Tester
- CURT
more information >
Featured Help Information
Instructions
Miscellaneous Media
Continue Researching
- Article: Brake Controller 7- and 4-Way Installation Kit (ETBC7)
- Article: Trailer Wiring Diagrams
- Article: Wiring Trailer Lights with a 7-Way Plug (It's Easier Than You Think)
- Article: How to Measure for Trailer Hitch Drop
- Q&A: Suspension Enhancement Recommendation for 2019 Toyota RAV4
- Q&A: 7-Way Tester Recommendation for a Land Rover with 7-Way and P3 Brake Controller
- Article: Brake Controller Installation: Starting from Scratch
- Q&A: Extended Ball Mount for a 2" Receiver with a 1" Shank Hole
- Q&A: Are There 7-Way Trailer Wiring Harnesses for a 2023 Kia Telluride
- Article: Testing Trailer Brake Magnets for Proper Function
- Q&A: Easy Way to Install 7-Way and Brake Controller in 2022 Toyota Sienna
- Q&A: Recommended 7-Way Tester that is Compatible w/ Ram Factory Brake Controllers
- Q&A: How Thick are the Aluminum Tandem Axle Trailer Fenders # HP52VR?
- Article: Roadmaster Vehicle Specific Base Plates