Charging Problems

[omw41]

1993 2.3l LX Vert: I am , but here is what I know. I replaced the voltage regulator and the battery. The cables/terminals to the battery are clean and tight. I have no blown fuses, but I have not checked the fuseable link off of the soleniod yet. Here is what hapens: even with a new battery in the car it goes dead as can be overnight, but when I jump it with my other car, it starts right up, the volt meter on the stock gauge cluster reads charging, and all is cool, until I disconnect the jump and then you can just watch the volts drop on the meter and the car just drops dead, and the battery is dead again. I mean, is it the alternator? That is the only thing I have not replaced, but I am just a shadetree and I am wondering if what I mentioned about jumping the car will help someone pin point my problem.

Thanks