1990 ford taurus fuse

in my 1990 taurus the fuse/circuit breaker for the horn/cruise control/lighters keeps blowing if I put more then 1 of them on at a time. These are the self resetting ones and shouldn't totally blow out. I have gone though 6 of them in 6 months of having the car. 3 in one month. I don't have a wiring diagram to see if it's a wiring problem in the back of the fuse panel but the spot where it goes in is sorta black at the slots so figured it is what keeps blowing it. I don't have much experience with changing them but always willing to try and learn.