2019 F450 looking for a key on power under the hood. Odd one

All of the cars I’ve owned in the last 10 years or so are smart enough to not let you leave any circuit energized for a long time with the engine off and the key or key fob away from the car. I leave the hood up, trunk open and doors open on all my vehicles frequently when there’s a need and all of them turn the lights off eventually and will not run the batteries down.

When I know one of our vehicles needs to sit for a few weeks, I open the hood or the trunk, depending on where the battery is, and hook up a battery maintainer to it. After a period of time that seems to be less than an hour, the hood or trunk lights go off. I have keyed and push button ignition vehicles, and they all work that way.

:):)

I can't speak to your exact situation, as I haven't been under the dash of a Ford in many years, but a lot of newer vehicles activate a lot of circuits just by opening the door. Perhaps that's what yours did?

I am concerned if a line develops a leak, the pump would run an I might not know for days. Maybe kill the batteries, or burn out the motor. Best to have it off when the truck is off in my opinion. If it does develop a leak, I would hear the pump when I start it and know to take a look.

Why do you need a switched power source for your Air Lift? I have mine wired hot and it works just fine that way. In fact, I discovered I had a slight air leak on a fitting when I walked by the truck and heard the pump run for no reason. Fixed it and now it doesn't.

I first used the fuse for the rear seat heat. Can't imagine that one being hot while the truck is off. I then checked a bunch more and they were all hot. Hood is open so in the morning I will check again and see if they are all hot or not.

Its just my old school brain that is having issues. Never met a vehicle with a fuse box that was hot when the power key was off. Its a push button, but the key is in my pocket. Maybe I should leave it far from the truck.

All what fuses are hot?
Functions that don't run with ign off should not be hot at the fuse box.
Where did you pull power from?
Whatever source you find should be fine because you only need ign power to trigger a relay, right?

Well seems odd. Truck was up on the lift all day. I just lowered it to wire things up. Fuse was hot. I'll go out in the morning now that it's back on the ground and the hood is open and see if it powered down.

I could use the upfitter switches but there must be some place that I can tap for power when the truck in in use and off when shut down. I'll see in the am if your correct about fuses powering down.

Fords cut the power to fuses/beakers after a few minutes of switch off. Thought about using one of your upfitter switches if you have them?