you probably have a short somewhere. use a test light to see if you definatly have a short. give one side of the light 12v power and put the other end of the light at the side of the fuse that doesn't provide power (with the fuse removed of course) if the light comes on you have a short. trace the wire to see if it is touching any of the chasis. also don't use bigger fuses, only use the factory recommended fuse. you'll end up destroying something more expensive than a fuse if you keep upping the fuse amperage. HTH