Sorry to hear that. I was going to suggest looking in the taillight housings for water. 88-91 CRX's and Civic's are notorious for water draining down from the hatch and directly on top of the taillights - the foam gasket over time develops leaks and the water runs right into the housing. When it gets deep enough, it'll slosh into the sockets and blow the fuse.

A solution (the one I used) is to silicon the the foam gasket to the taillight housing and then silicon that assy. to the body. This will keep the water out of both the housing and your spare tire well. I also ran a bead of silicon across the lens/housing seam on top....

Maybe this info will be handy in the future.