Dodge charger won't start?

Ok my buddies 2008 Dodge charger sxt won't start. We were trying to install and amplifier and we taking off the postive on the battery and it sparked. I believe we set off the security immobilizer. Last night the engine wouldn't crank and the low beam headlamps wouldn't come on. Today the engine will crank and the headlamps work but It still won't start. Can someone help?