I keep blowing my tail light fuse in my 01 Protege. Every time I turn on the tail lights, the fuse blows.

Yesterday I replace my headlights. They work great. But my tail lights, dash lights, and
front parking lights do not work. I replaced the tail lights a few months ago, and they
worked fine until I replaced the head lights. I removed the parking light bulbs and tail
light bulbs, and the fuse still blew. I checked all of the sockets with a multimeter, and
they all read less than 1 ohm of resistance. I have four fuses left and would like the
problem fixed before I run out. Any suggestions?