This one threw me for a while, there's an access panel on the left side of the dash. Unless you really look for it, it's hard to see, it just prys open, and the fuse panel is behind it. Good luck.
In the fuse box under dash, left of steering column.
bad bulbs and or blown fuse
#4 fuse blew
Yes, some vehicles have one fuse that protects the gauge/dash cluster circuit.
Look for a blown fuse.
Between the driver door and the dash. And also under hood next to the battery.
Probably a fuse or a loose cable. Try that first.
a fuse or a bad connection where it plugs in to the dash
It is under dash on left of steering column. It is not easy to get at.
Typically this is for the instrument cluster, i. e. the dash gauges.
If a 1999 Jeep Wrangler dash gauge stops working, check the fuse. The fuse may have blown out and will need replaced.
Do the interior lights work in the gear selector or the climate controls? If none of them work, suspect a fuse or something else. If it's just behind the gauges and all have gone out, then the board behind the gauges may be fried. But assuming none of those are the case, you'll need to remove the dash and the bulbs are located behind the gauges. Not a task for the timid.