I left the battery on charge overnight. Voltage now at 12.75. Started truck after removing charger and all problems are still there.

Yesterday I removed cables and cleaned up post and connectors, all looked good before and after. Cables were off the battery for over 20 minutes.

 

Good call.

So then, everything is good to go now? If so, what you did was called KAM reset, Keep Alive Memory. Bet your trans shifting was a bit goofy afterwards?
Humor me everyone. When weird crap goes on, a KAM reset sometimes works, the simplest, seeming unrelated issues magically clear up.
I was doing some lighting mods, got done and proud of myself, except I no longer had cruise control. I had worked on nothing that had anything to do with cruise. Out of desperation, I did the KAM reset, cruise came back. I have zero clue as to what caused me to temporarily lose it. Bloody computers, they do what ever they want I guess.

 

I amend my previous advice to "just charge the battery" not to "Just remove the battery from teh truck and charge it overnight". I guess that will do a KAM reset as well as get the battery topped off with one action. Means you don't have to overthink things either. IO guess the ultimate would be to do that, then reconnect the battery and leave the truck for another 8 hours to make the BMS reset? haha so many "smart" systems in these trucks.

 

So all is still not good. You had it parked for a bit, outdoors or indoors? Is it possibly an animal made a meal out of a grounding cable somewhere under the hood? I have never really looked over my 2016 to find the body and chassis grounds, but did have an issue on my 1990 with the braided ground cable between the engine and body needing replacement ... not as many electronics in my 1990 XLT Lariat, but it had power windows, AC, AM/FM Cassette, a 300CID and 5Sp Manual.

 

I’m still believe the battery needs to be replaced. When you get your new one, put it on a charger first for a few hours to make sure it’s fully charged.

 

If you know where you'll buy your battery in advance, you can have them fully charge it prior to picking it up.
It'll save you the hassle, especially if you don't have a heavy duty charger.

 

Agree with the posts above.....it’s time to try a new battery.

Have nothing to lose - if it fixes your problem, great. If it doesn’t, you would have to stick in a new battery at some point anyway so you haven’t wasted any money.

Just better to definitely rule out the battery, a potentially simple fix, before you delve into the complicated stuff.

 

AGM related.
I replaced my original battery with a superstart AGM size 65 from O’Reilly’s in December. In August I had a weak start incident and brought it in and had the battery and alternator tested. They both tested fine. A few days later I had another incident and asked to have it load tested and it failed! I highly suggest that you have it load tested if not replaced.
It will be my last AGM.

 

I'm not familiar enough with agm to make any recommendations. If it were me tho, I'd replace the battery and not with a Ford. Just too typical of battery symptoms. At minimum, I would have your current one load tested.

 

4 Years for a battery .... I would be jumping through hoops. Hey ... mine makes 4 years this month by mfg date of truck. Lets see if it makes it through our 3 or 4 weeks of winter. I will be getting another Motorcraft one if I can.

My 2012 Regal Turbo is on it's 5th battery, first one replaced under vehicle warranty when it started oozing at about 3.2 years (the best one), that replacement lasted till right after the car warranty finished ... how did they time that. Next was Diehard that died after sears local service centers closed but still had a few months warranty, then came the already a year old when I bought it new Duracell from Sams, got 11 months but replaced free .... so it's replacement was 1 month from mfg, still going good but not a year yet, gotta love 3 year free replacement warranties. It takes AGM batteries and that car doesn't get driven as much anymore as truck no primary, so could be reason on last 2 batteries.

 

I would check for a power loss to the passenger compartment fuse panel. Seems like your symptoms are controlled there. https://www.startmycar.com/ford/f-150/info/fusebox/2016
I would also check the power distribution box high amp fuses, like #12 and #13. I have no wiring diagram so I can't tell you where the main power feed for the pass. fuse panel comes from.

 

Another vote for replace the battery and go from there....