I just changed the alternator on my car and it was working fine but when i park it i still have to boost the car, i figured this was because the batterry was dead for so long,and its probably not fully charged. However today i went to start it and i put a small booster pack on it, tried to boost it and nothing happened. It didnt crank at all. Keep in mind the booster pack is really small and not heavy duty at all, but i was wondering could this be my battery or my starter? If the starter was dead would there be any crank at all? Anyways im going to buy a heavy duty battery charger tomorrow and see what that does..

have you tried 'jumping it' from another car? If the car starts, it could be the battery, or maybe bad wiring somewhere that's draining the battery.

those small booster packs are okay, but they don't last very long (maybe a year or so) and don't seem to perform as well as the bigger ones.

When you turn the ignition does any sign of lights appear?! That would be your battery. The alternator ground wire is usually a flimsy pos. Those I have a small booster pack and it works great on these small cars. It's saved my hide tons of times. If it's not even cranking and you know theres power coming from the booster, maybe your starter is jammed? Easiest way to unjam a starter is to put it into 4th or 5th and rock it, but I haven't heard of a starter getting jammed on an e21..

From my saab I remember reading in the manual that then you try to crank it that things can arc and just completely bypass the starter, given that you have power.

when i turn the key with the booster pack hooked up all the lights work fine except headlights and turnsignals, but still no crank. BUt when theres no booster on there none of the lights work except the ones on the cluster (oil light and so on)...so i dunno if its just that the booster pack doesnt have enough power or not..i havent tried boosting it from another car since this happened, but i just bought a heavy duty battery charger and i'm gonna see how that works out later on today. Wouldnt be surprised if my battery is trash.