'90 Seville parklamp fuse blows
 

I have a 1990 4-dr, 4.5L, V8 Seville. The problem I'm having as of late is with my parklamps. It keeps blowing every fuse I install. I was on my way home and I was informed that I had no brake lights. So I stopped at the nearest gas station, turned off the car and the lights, and then tried turning on just the park lamps by themselves. Nothing. So I try turning them back on w/ my headlights, once again, nothing. I finally checked the fuse in my glove box and it was indeed blown. So I go into the gas station and buy the replacement fuse (15), a pack of 5 actually. I install it, attempt to turn on the parklamps by themselves and "POP!" BLOWN FUSE!!!!!! I try this 3 more times and the same thing happens. I don't know what to do. I even tried a 25 in its place and it blew that one also. Can someone give me some suggestions?
Thanx in advance