Dead battery

[LHaven]

If we're positive that it is (and others seem to be) then it's almost surely a small flash RAM, which doesn't need power to remember stuff.

The only datum I'd be concerned about losing and having to re-setup would be the correct level for the trailer. The re-hitch position isn't that crucial to me, since I have a travel trailer (you lose it whenever you move the legs manually anyway). And if worse came to worst, I could always re-store the level myself using the manual procedure in the booklet.

[MarkEHansen]

Well, it definitely remembers the level position or you would have to re-establish it each time you put the batteries back in - and what would be the point of that?

As LHaven said, it's would be stored in flash memory. Most microcontrollers (which is the brain inside the control board) would come with flash memory built-in, so it's easy to implement from a design point of view.

I honestly don't know if it doesn't also remember the hitch position, but it wouldn't surprise me either way.

[skmct]

I my have answered my own question. Not returning to the hookup position may have more to do with the truck height. Loading in bed and air pressure in the air bags could account for what's happening.

[LHaven]

I guess you could tell more from the failure response. If the unit has forgotten the hitch position, it will generally just refuse to respond to your request to return to it. If it thinks it's returning to the hitch position but it doesn't match up for you, then your truck height or terrain might be the problem.

[Todd727]

Originally Posted by B27

It’s an F150 issue. Hook up the truck then start it and watch the message centre. It will usually indicate trailer connected but battery not charging. Put vehicle into gear then back to park will activate the charging relay. It’s a protective measure put in by Ford so it doesn’t blow the trailer fuse. You’ll find that light will still work but that’s it

99.9% correct. It affects all Ford trucks after ~2014. It may affect all Ford vehicles. Not usually a problem, but a pain for those of us that use a transfer tank to carry off-road diesel. If anyone has that problem, they just need a small resistor between any of the lights in the trailer plug and ground.

[Pete54401]

I work for a Ford store (41 years on the sales side) and I can't count the number of times someone has had an issue with their trailer battery not charging, and everyone wants to blame the truck of course. This is a common "problem" on later model F-150 and Super Duty though typically the fix, as long as not a trailer-side or wiring issue is that the truck needs to "recognize" that the trailer is plugged in. Here is a page out of a 2018 F-150 manual describing the very simple process. It's magic.

[JRTJH]

Pete54401,

Great information, thank you for pointing it out. As you said, "It's a common problem" (though if both the truck and trailer are operating properly, it's usually an "operator error" in not following the owner's manual instructions)....

Again, thanks for highlighting the proper way to connect the truck and trailer and get them to "recognize the connection".