Cobra alarm problems
 

My cobra alarm is playing up. It won't re-arm if the car is left unlocked (it used to after 30 seconds or so if the car wasn't started) It locks and unlocks fine but when I start it it beeps at me for a short while then goes off but the LED's still flashing on the dash board. It's a cobra A6019 HF MK2 anyone got any clues??? could it be the immobiliser relay???

just a thougth, but how healthy is your battery? does it struggle to turn then engine over a bit?

No problems there battery seems fine. tks.

I may be wrong but. on my scooby it only re-locks itself if you dont open a door. ie if you un-lock the car with the remote, but then dont get in the car alarm will re-arm and lock the doors.
This is a feature, in case you catch the remote when putting your keys in your pocket etc.

might seem obvious,but what about the battery in the key fob?