Chrysler Repair: Battery wont hold a charge...battery or short?, negative battery cable, chrysler lebaron

Question
I purchased a 1989 Chrysler LeBaron with 107,000 miles on it.  The car sat for years until recently  The person I bought it from said he put a good battery in it but a few weeks after I bought the car it went dead, I charged the battery for three days then it ran fine for three weeks now the battery is completely dead and will not hold a charge, after I charged the battery the first time. With the car running i removed the negative battery cable and the car did not die, does that mean the alternator is ok?  I'm going to put a new battery in it, could a solenoid be my problem or do you think the battery was bad, it was purchased in 2004. Please help me

Answer
Hi Victoria,
The engine continuing to run while the battery is disconnected is fine. If the battery won't take/hold a charge then I suspect the battery is weak or maybe has an intermittent short. But try to charge it up when disconnected entirely from the car. It could be there is a short in the circuitry of the car that is intermittently draining the battery even though the ignition switch is off. I can tell you how to find that out if you have a volt-ohm-ammeter, but first see how the battery take a charge "on the bench" (e.g. without being connected to the battery cables, no need to actually remove it from the car). Then let me know.
Roland