There is a sticky at the top of this forum that is five years old...
https://www.f150online.com/forums/el...er-repair.html

Great thread, many positive responses from happy members.

I had the same problem, odometer goes out, comes back on randomly, sometimes flickered.
I just didn't want to tear into the dash, so I've been living with it for three years now.

Four days ago, I swapped out my nearly 10 year old OEM battery for a new one.
My odometer light has not flickered or gone out once.
In fact, it's brighter than it has ever been during the day.

I guess the point of this thread is, if you have the odometer problem and you need a battery,
do the battery first, it may save you from having to tear into the dash.