I just bought a 1992 Ranger with the typical alloy wheels. My problem is the guy I bought it from let the coating wear and crack, which allowed water to get underneath. Is there anyway to clean this or is sanding and repainting my only option? Any advice?

Repainting is about your only option. Instead of sanding though, I would use a paint remover. It's much less likely to cause damage. It dulls the wheels, but you can polish them back out. I've not had a lot of luck with clear coating wheels again, I usually just polish them every couple weeks.

To pull that clear coat off I would recomend some acetone, and if that is not strong enough go up to lacquer thinner. You can recoat if you want to, but if you don't try and keep a couple of coats of wax on ther or the will get a lot of dirt inbeded in them.