should i panic? its acting wired...

Just drove my 88GT around all day with no probs whatsoever, then today i took it to the painters to get a brand new coat and a friend and me took apart almost the intire car - doors front fenders frontbumper cover and rear.. all the skirts ect also. the wired thing is when i started i turned on the engine and after around 20 secs it died. at the time i dident think much of it but now the car wont start at all!!!! shouldent the car start eventho the doors are off? i mean does the electrical in the doors have anything to do with the engine not starting? - do i need to run some kind og special check list when the battery has been disconnected?
someone please help me! i checked out all the wires ect to make sure that nothing had been pulled that shouldent be.. nothing is (was one fitting but it dident help putting it back together?)