12V Power Pin on 7-Way of 2013 Ford F-150 Isn't Receiving Power

Updated 10/25/2025 | Published 03/13/2018

Question:

I own a 2013 Ford F150 XLT Super Crew with the EcoBoost V6 that I purchased used in 2014. I recently purchased an enclosed snowmobile trailer new with a 7 pin connector. The truck came with the 7 pin receptacle. When I first connected the trailer, all lights worked with the exception of the interior lights. In researching the issue, I discovered this year, make and model came with a relay and fuse not installed. Many people on many forums stated when they installed the relay and fuse trailer tow battery charge relay and 30 amp fuse, the interior lights worked. The relay and fuse were not in the glove box so I purchased a relay and fuse and installed them. No luck. Interior lights still do not work. I hooked the trailer to a friends Chevy just to make the interior lights worked, and they came on. I have checked the wiring and the pins with a circuit tester with the truck running and just the ignition on. Nothing. Im beyond frustrated at this point.

asked by: Mike

Expert Reply:

Since you aren't getting any kind of power signal at the pin in the 1 o'clock position on the 7-Way on your 2013 Ford F-150 and you have installed the relay/fuse that is needed, my first thought is to make sure that there is actually wires running to the back of your 7-Way for those pins.

For some reason (and it isn't always consistent) truck manufacturers will sometimes install the 7-Way but not run the wiring all the way down the frame to the 7-Way. Check to make sure that the wiring is there, and if it is the next step would be to test the wiring itself. If the wire for your 12V power is connected to your battery and the wire itself has power then you need a new connector like part # HM40975.

If it doesn't have power then you could potentially have a short somewhere on that circuit and the rest of the wiring needs to be inspected.

Let me know if that doesn't fix your problem and I can help you troubleshoot further.

expert reply by: Jon G

Thomas W.

10/24/2025

Hello. I have a very similar question. My mechanic won't install the relay or fuse because the alternator could get overloaded with the extra amp needed to power camper. What do you recommend?

Jon G.

10/25/2025

@ThomasW Unless you have a weak alternator or you're planning on drawing a LOT of power to your battery bank you'll be just fine. That 12V pin only supplies a trickle charge so it basically just keeps your battery level from dropping instead of actually charging it. To actually charge your battery bank you'll need something like the Redarc In-Vehicle BCDC Trailer Battery Charger # RED36TR along with the wiring and fuses like parts # RED76FR and # RED86FR. Is this more of the route you're thinking? Or are you just looking for a trickle charge?