My system in my car wont power on!!! help?

ok i just got a new cap 10 farad and got it all wired up and mounted was working good...the next day went to my car and my cap or my amp wasn't on checked both of my fuses they were good....i still didn't think i was gettin power to it so i touched my + to my - realy quick and got a good spark....so i dont know what else it could be any ideas.....thanks