Won't Start on 1998 Chevrolet Monte Carlo

My car won't start the battery is fully charged, all fuses and relays are good but when you turn the key to start it it just won't do anything. I can start it by hand at the starter but it will run thirty seconds then die. There is a security light on the dash that stays lit how do i fix this and could this be my problem or is it the switch in general

Asked by for the 1998 Chevrolet Monte Carlo
1 answer
if you have another key, try it first. if not, the most common failure is the wires break in the lock cylinder.