94 Gmc Jimmy Won't Start!?!?!?

[justinge3]

I just bought a 94 jimmy and been driving it for about a week. Well last night I installed a new pioneer cd player. It was really cold outside so I did it with the truck running. I got it all hooked up and drove about 20 miles and came back home. Well I went to start it about 1 hour later and there was nothing at all. Wouldn't even crank/turn over. The wierd thing was that my flashers were going on and off too with a beeping noise. My battery connections are really tight and I still have all my interior lights, guages and headlights working fine. I checked all my fuses and there all good. Well I unhooked the battery all day thinking maybe it will reset something or fix the problem. Went to put the battery cable back on and still wouldn't start. There are no noises are anything either. My digital dash flashes on and off just like the flasher lights. I don't know what to do at all. Maybe I screwed something up when I wired the cd player in. I can't afford a to take it to a mechanic HELP