I have a 21 Lariat PowerBoost. The following electrical issues just seem to come and go:
Electric tailgate sometimes does not rise. I have to manually shut it and then it's ok
Power running board on driver side sometimes does not come out when I park and exit seat (I almost fall over if I fail to check). I have to use key fob to bring it back out again
Drive mode fail light comes on and then I rotate dial again and it is fine
Yesterday I had a light come on that said "Pro Power turned off" then it went away

I could never duplicate these issues at dealer
Is this common b/c of the complicated electronics?

 

Welcome to Ford F150 ownership.

 

Me thinks it's battery time. When weird things start happening, first thing I'd do is a KAM reset, and suspect old battery,
Now a days, in these electronic laden trucks, batteries don't last as long. Don't rely on Auto Zone doing a load test.
I even had mine at the dealer after weird things started happening. They load tested it, came out good. Then they blamed it on the cold weather, down around 15F or so. Well that didn't hold water in my book, so, after a couple weeks, I just went ahead and replaced the battery. Funny how everything cleared up.

 

You may very well have a battery issue but on the power running boards front if you are getting only one not working at times it might be a lack of lubricant issue on that side. This too can be an intermittent problem.

 

Thanks for the reply, I will check out the battery

 

Thanks! I will check out the lubrication

 

You need to check the aux battery. You can upgrade the size of it. Fixes a LOT of the Powerboost weird electrical issues.

 

Thanks, I didn't realize there was a 3rd battery

 

Not many do and when it starts to go south a lot of the Powerboost issues start to pop up. The truck relies hard on that tiny aux battery.