We used to have a 86 buick park avanue that ate alternators, why was because we ran the radio alot without the engine running. What would happen is the radio would put a slight drain on the battery so when the car was started the alternator would go into full charge mode until it burned itself up. Other times it just depends on where you get the alternator. We went through 4 at advance auto parts until we got one that lasted over a month.
My dad`s 98 GMC will start without the alternator, but it won`t stay running 10 seconds there after, or if you start it and remove the battery cable it goes dead on the spot. computer vehicles take alot of juice to run being they have far more electrical accessories to operate. before the computer days to find a 55 amp alternator was common, now it`s common to find over 100 amp alternators. Have the alternator checked, if it checks out okay you`ll know the problem lies elsewhere. Yeah some haven`t heard of the alternator having a effect on it, but I can`t swear it applies to all vehicles, I only know it deals with some from personal experience. If the alternator is putting out no juice and the battery has enough to turn it over doesn`t mean it has enough to operate the rest of the system. When you jump start a already hot battery your increasing the power to likely enough to make the vehicle run.