I've jump started a few cars before always having my engine runing with no problems until last weekend when I jumped a friends van, I thought every thing was ok parked the car in the shade and carried on for the day. When I went to leave in the evening the alarm remote wouldn't work after breaking apart a new £30 sealed remote thinking it was the batterys then finding out it had lost the rolling code in the alarm, there's no key to overide on factory fit sigma alarms you need the remote to do this! Anyway after having the AA out then having to wait for a recovery truck and only to arive home at 3.30am monday morning to nip inside get my spare remote and drive the car off the truck!!!!! So if you've got a factory sigma alarm make sure you take a spare remote if youre traveling away from home!
Warren