I've recently had an issue starting the car. The alarm light on the dash would continuously flash, eventually after several attempts of removing the key it would stop flashing and start.
Through some advice I replaced the battery the ignition barrel and exciter ring. The car is better but still occasionally will have the same issue.
What else could it be?
Thanks
Mike

 

Fuel, Air, and Fire. Solve that and it runs. Take it to one of the auto parts stores (ADVANCE, OREILY) and let them run a code diagnostic and see what happens.

 

Would those problems make the security light flash continuously?

 

Yes, sometimes it will, but this sounds like a connection, adjustment, or a sensor. All electrical is Fire. If you get nothing, I would take it to a Jag expert/dealer in your area. Cars that shut off while driving are VERY dangerous.