I agree with carfixer007, but before I would get into all of that I'd get a cluster from a donor and try it as a step of elimination . . . unless I found myself trying to diagnose this too far from a junkyard for that to be feasible.

the PRND21 indicator is one thing and one thing only no fuses are bad, no wiring is bad it'* four resistors on the back of the cluster board done this on my century 4-150 ohm 1/2 watt Resistors a 6.00 dollar fix and total 30 min repairs not hard at all
And FYI cluster change would display the mileage of the donor car mileage is stored in the cluster the resistor fix keeps your cluster so you keep correct mileage

Agree. This is why I suggested using it for diagnostics only. What I didn't mention is that it could be handy for cluster parts should OP want them later. If there'* one available, it would be easier to try a cluster than have no direction to start troubleshooting.

Wanted to follow up with what happened. Took the cluster panel / circuit board out of the instrument display. Sure enough, one of the 4 resistors on the right side was missing, and one was partially hanging loose - just as others have described. With small needle nose pliers I took the all of them off and soldered four 150-ohm 1/4 watt resistors on each connection. Plugged display back in last night and boom, everything is lit. And my Century passed 100K by 206 miles when display was out. This was a very simple fix if you know what to look for, it was the first time I've ever done a repair like this and first time with a solder gun. BTW the $3.99 solder gun from Harbor Freight works fine. The biggest issue is having enough patience and soft touch to not break anything as you pull dash apart as needed, and I managed not to mess anything up. Thanks to you all for the fix help. Took ~90 mins all in counting setup, clean up, put back in, and $6 for a pack of 10 resistors from Amazon mailed to my home.

Pictures would have been nice.

OK, well that was sort of crappy. But my issue was exactly like the numerous other posts about this as well as YouTube videos showing the complete job and the 4 resistors. Thanks again for those that helped me with my issue, I do really appreciate it.

Thanks for letting us know what fixed it!

Yes, pictures of what you repaired would have been nice. But, we don't have the 'numerous other posts' WITH pictures or the 'Youtube' videos abound on the interwebs.