Hello,
My 1999 F-150 has an odometer problem. After about 30-60 seconds after startup, the odometer either fades out or disappears. It sometimes comes back after driving, but usually stays blank

 

Sounds like you may have the intermittent odometer problem. Others have had the same problem. In August I posted a repair that worked for me, I haven't heard yet if others found the repair worked for them. Here is a link to my prior post:
https://www.f150online.com/forums/sh...ighlight=Upton