Immobilizer red key light is on
 

So my battery went dead and after recharging it, a few days later, the red key light for the immobilizer is now flashing everytime i switch of the car and remove the key...Its a very quick flashing but never did it before...is this normal? Will this drain my battery quicker? Can/should i switch this off?
Many thanks

Sounds like normal behaviour, perhaps you've never noticed it before. they all flash like that when not running. as long as its not illuminated when the cars running you have no issues

Thanks mate...Yes, it only lights up when i remove the key...Ill just have to get used to it.

what happens if its illuminated while the cars running

That doesent happen to me but i have read that if thats the case then it means you have an issue as it shouldnt be flashing or iluminated while the car is running. Have it checked.