hi can anybody help me, i have a h reg fiesta rs turbo, the problem is that it does not hold charge, ive had a new alternator and battery and this work fine for a few weeks then it wont start, if i jump start it off another car it fires up first turn of the key and runs fine for a day or so then im back to a flat battery!! i have an old cat 1 alarm on the car ( gt 16t ) this was on the car when i brought it its been on there since the first owner according from my paper work, it has a imobiliser on, i was thinking because this is so old school could this be killing battery?? any ideas would be great!! cheers!!