I have a 1993 ford crown vic lx. The taillights won't work. I checked the fuse, it's ok. What else could it be?

 

If you have a test light, check at the light socket to see if there is current there when the headlights are on. If there is current there, check the bulbs. There is a possibility that one of the bulbs blew long before the other one did. Let us know.