#15 fuse keeps blowing
 

I have been using an air pressure pump that plugs into the cigarette lighter for about 2 weeks because I had a tire that had a slow leak in it. Well, now my #15 fuse keeps blowing constantly. This fuse operates the door lights, the dome lights and the door chime when you open the door or leave the key in the ignition. I need help determining what's going on. When I first replace the fuse it works fine, but later in the day it appears to blow again. Thanks in advance. (Car is a 1985 500 sel.)

check the lights in the bottom of all four doors to see if one is broken and may be your short.