i have a 1996 honda accord and the back up (radio) fuse is 7.5a and my staero is 15a so if i was to put a 15 or 10 amp fuse in would it be any better for the staero or could it cause dammage

 

Bigger fuses will not help anything. If there is a short the wires, it will now melt or burn before the larger fuse blows.

If the fuses are blowing you should run a fused wire from the battery to the radio. If the new fuse on the new wire blows, then you have a bad radio.

 

Don't forget that your ECU is also on that 7.5A back-up fuse as well. Not advised to start upping the fuse just for a stereo. Your stereo should have it's own in it anyway. If it is a 15A you won't have to worry about frying it on a 7.5A circuit. I'm no stereo guru by any means. I just installed my 15A stereo using the 7.5A circuit and had no problems. If your stereo actually requires a 15A circuit you should find one to wire it up too.