I have a 2016 F-350 Super Duty. I wanted to confirm that I indeed had 12 volt Battery/Trailer Charge at the 7 wire connector. I found out that on my truck the 12 volt wire is controlled by the ignition. My question, is this normal, and can it be changed to constant without too much hassle?

 

Never mind, I think I found the answer. digging deeper the 2016 Super Duty's 12 volt connection only has power when the BCM senses a trailer connected, and the trailer brakes are applied. Correct me if I am wrong but as long as I have the key on, transmission in drive, it will continue to have power to charge my trailer/fifth wheel batteries once I have applied the trailer brakes until I turn the key off or put it in park.

 

That is correct. Press the brakes while the engine is on and you'll have 12 volt power through the 7 pin trailer plug.

 

You have something wrong. I have a 2016 F350 also and the terminal marked "+" will have battery voltage on it anytime the key is turned on....period! You don't have to be in drive, you don't have to be connected to a trailer, you don't have to do anything other than have the ignition key turned to the on position.........with or WITHOUT the engine running! And ther reason that it's wired this way is to prevent someone from running the battery(s) down in their truck if they would stop for let's say an overnight, leave the trailer hooked up to the truck and NOT unplug the trailer 7 pin connector. If you didn't need to have the ignition key turned on and that terminal was hot all the time and you did what I was just talking about (leaving the trailer plugged in overnight or for a couple of days), your truck battery would most likely be deader than a door nail. Hope this clears it up for you. That is the voltage that will be used to keep the trailer onboard battery charged.....or at least trying to be charged. There is a totally separate terminal that supplies power to the brakes on the trailer....maybe you were thinking about that one instead.

 

Thanks for the information, I will look further into it. The main reason I was asking is I am going to be adding some LED lights to the truck bed and was looking for a easy way to get constant 12 volts without having to run a separate wire to the rear of the truck.

 

I tapped the running lights off the seven pin in my bed. Not elegant, but simple to do, but I do have to switch my running lights on. I thought the charge lead change so a trailer had to be in the circuit was a model change in 2017, but could be wrong. There is an earlier thread in the forum where it was discussed.

 

You may be correct on the change to the 2017 model and up......I don't know. Since the OP stated that he has a 2016 and mine is a 2016, I could state with no uncertainty that it works as I described on the '16 model years. I thought it was like that, but I did go out with a meter and check mine yesterday before posting, just to make sure it was as I was 99.% sure it was. Mark your calendars folks........I was right today! ......and please......no one tell my wife I was right!

 

Just checked mine and yes with the key on there is power at the 12 volt battery terminal in the 7 wire connector.

Don't worry "What Happens on the Ford Trucks Forum, Stays on the Ford Trucks Forum"

 

Here's a link for the 2017 change: https://ford.oemdtc.com/2482/trailer...d-f-super-duty.

I think the years 2011-2016 the charge lead goes hot with the ignition. The change is an example of over-engineeriing from my perspective.

 

I agree, over-engineered and definitely NOT a step in the right direction!