85' prelude stereo problems

everything on and in the car is perfect,but i cannot get a stereo working in there.there was a working one in it but now i got split wires all-around.i do the basics by only connecting the black red and yellow wires but but when the car turns on, i fry a fuse.if i reverse the black and red wires nothing happens,even with a ground.if you have any helpful info please reply.  

hey man...you shouldnt go in there connecting random wires assuming they are all colour coded.....first thing u need to do...is pull out multimeter...set it to voltage 0-20volts(if its not automatic ranging)...then u need to find your constant power wire by finding a wire (in the cluster of wires behind the cd player)that is 12 volts with the car off...then find the 12 volt power wire by turning ur key into the accessory position...then look for 12 volts on another wire...then when ur done that.....connect one end of ur multimeter to the ground on the battery....and turn your multimeter to continuity test...then look for a ground......try connecting ur cd player now and see if it works