I have a '98 Explorer and just experienced this problem. The radio, CD, and tape deck are functional in every way, its just that the clock/radio display is dark and so you can't see what station you're on, CD track, etc. Apparently it's a common problem; I found it very disappointing and annoying.
Thank God for D Harrison, who posted a fix in 2002 on this group. I couldn't reply with my thanks because the topic is more than 30 days old, but I thought I'd include a link and post my gratitude.
I also want to post a link to a very helpful site that shows how to fashion the radio removal tools:
Thank you for this group, thanks for Google, and thanks to Mr Harrison!