Hello, I hope the following is of assistance.
The light you describe is the immobiliser warning light, when the car is turned off this light flashes around once every second. When you switch the ignition on the immobiliser light should stay on for a couple of seconds then go off, this is normal operation, if it comes on then flashes fast this means the immobiliser is still active and the car won't start.
If it is the immobiliser stopping the car from starting then check the battery connections and the fuses for the immobiliser system these are in the fuse box inside the car and are fuses,12, 14, 15, 16 & 30.
Start with confirming if the immobiliser is operating as it should, let me know if I can assist further or if you have more questions regarding this and I'll reply as soon as I'm able to.