I bought my 2010 Ultra this past May and the front left speaker would only turn on at higher volumes. When purchased, it had J & M Rokker 600 watt amp and XX Speakers front and back. I originally tinkered around with some wires but didn't worry about it too much until this winter when its stored. I tore off the front fairing and really dug into it. Swapped speakers, wires and RCA's. I even took out the radio and amp. I tinkered around with that combo a bit and re-installed. It now works at all volumes. I'm assuming a bad connection somewhere. But after that when I was putting everything back together, I noticed one of the two 30 amp fuses mounted on the amp was out and laying in the bracket. It was there for some time because of the dust accumulated. I grabbed a new fuse and threw it in there since the old was was bent a little bit from sitting in the corner of the bracket. I guess my question is, what is the purpose of two 30 amp fuses as opposed to one 60 amp fuse? I'm confused in that regard. If one of the fuses is not in, wouldn't that have an affect on the amp in some way? Thanks for the help.