While helping my dad tow his travel trailer home for the winter, I discovered that my 2018 F150 does not have a constant 12V power supply at the trailer connector. My exhaustive research has me find that this has been commonplace on 2015 and new Fords (and maybe more than that). We confirm it was the truck after connecting two other GMs to the trailer. The camper slide-outs would work on those trucks, but not mine. Only when the truck was running, standing on one foot, and some other stupid crap, could we get 12V power.

Knowing that, I'm baffled as what to do. I have an enclosed snowmobile trailer with interior lights that pull from the 12V constant power (worked great on my last truck - GM). Many times when we are staying at a hotel for the weekend on a snowmobile trip, I just need to get in the trailer for something. So we go out to the parking lot where the trailer is still hitched to the truck, open the side door and turn the light on. I'm finding out I can no longer do this with my 2018 Ford.

So here's my question .... Is there a way to get constant 12V power at the trailer harness without having to run a specific wire from the battery?

 

The "smart" trailer connector on the 2015 and up doesn't energize the charge pin on the seven pin socket unless the trailer is connected, you have set it up in the trailer menu and you have to press the brakes after connecting it. To the OP:
1.Try to set up the trailer in the dash trailer menu and make it the active trailer. set it to "connected".
2.Connect the trailer via the plug
3.Step on the brakes once to activate the brake lights on the trailer.


Not guaranteed to work, but your best hope using the "smart" connector.
If this doesn't work, I would change the type of brakes you have the trailer set up for, ie. "electric" vs "hydraulic over electric", "none?"
then try step 2 and 3 again that way.


I hope it works for you.

 

Thanks for the response, and that helps a bit. So, let's take my enclosed snowmobile trailer for example. That trailer is already setup in the trailer dash menu and has electric brakes. And here's the scenario ... I have the trailer hitched and connected to my truck, and the whole thing is simply parked in the driveway. But I need to run outside and get something out of the trailer and it's dark. I just want to open the side door and turn the interior lights on, grab what I need, then close up and go back in the house. From what you are telling me, I can't do that. The only way to turn the lights on is to essentially start the truck and wait for it to recognize that a trailer is connected. Only then can I turn the interior lights on in the trailer.

Is that right? If so ..... that sucks!