This matches my symptoms exactly. The red light and alarm beeping gets your attention! I hope a new switch is all you need as well.It will get you FULL ATTENTION... It will be an interesting conversation w/Ford today. I farm for a living and have been around equipment of my life. I really dislike the electronics that modern tractors / harvesters / trucks now have . Its great when they work , but often are not trouble free -( I use the Sears refig 1965 model in the shop that just runs vs the GE 2015 in the house . We know the GE tech on a first name basis )
As for the truck I think its electrical :
I will report back...........
- will go away by only moving shift to park or neutral
- warning says LOW / Gauge shows ZERO
- only at a full stop -