electrical problems

a buddy of mine has a 86 firebird. it has now got an aftermarket cd player in it. the problem is you can not have power going to the the cd player when the head lights are on. as soon as you turn them on it blows a fuse and the dash lights and tails lights automatically go out. rewired the cd player to an empty slot in fuse box and the problem still persist. im drawing a blank on this guys. any possible solutions??? thanks

My first guess is that the dash illumination wire to the radio is not right or chaffed?