Couls this be a fuse issue?
How do I replace a dash light, can't see the speedomenter at night on 1999 Mercury Villager
If the problem is with just the one gauge, it is probably not a fuse issue. The back of the instrument cluster is covered with a printed circuit board. It supplies the power to the bulbs, etc. You may just need to clean the area around the hole for that bulb, or replace the bulb. you will have to remove the instrument cluster to fix this problem. You can by a DIY manual like Hanes or Chilton from your local auto parts store.
did somebody turn the dimmer all the way down by accident?