Alternator - Voltage Regulator, WTF Options

[Mblizzard]

Ok seems simple. Voltage light on dash on. Battery dies. Replaced voltage regulator with a wells VR650. Light on dash off. All seems good. But voltmeter shows the voltage dropping the longer the car runs until it dies. Voltage does not change regardless of engine speed.

Put the old regulator back on. Light on dash stays on regardless of engine speed. But voltmeter shows an increase in voltage with engine speed. I have not gotten the battery charged yet to see if running the engine discharges the battery.

I am at a loss as to what try next.

[Tom]

Mblizzard,
I also am not an expert, however, my understanding of alternators and voltage regulators are as follows; the voltage regulator regulates the current applied to charge the battery depending on a reference voltage from the battery, less battery voltage = more charging current. If the reference voltage is suddenly removed, (equals 0 volts), the the alternator tries to put out max current all at once. The diodes that change the AC voltage of the alternator to DC voltage for charging the battery are rated at certain voltages. In case of a sudden spike exceeding the diodes working max voltages, they can fail either in the open condition or shorted condition, either case will cause the alternator to be inoperative until repaired.
I remember in the days of generators back in the 50's that what you did was an acceptable way to check if the charging circuit was bad or the battery was bad. Not so for the new, ( after 50's) alternator equiped cars. Call up a mechanic that you trust and ask what they think. Most of the owners manuals nowadays have something in them about disconnecting the battery when running to protect the computer systems yes, but that voltage spike would destroy not only the computer, but the alternator also.
I hope this either helps you understand the alternator/regulator system in our cars or promps you to seek additional knowledge to improve your understanding. As I said , I am not an expert, just repeating what I have been told for many years.
You mentioned a center console change, maybe the previous owner has done some wiring changes that you are unaware of that could be giving you some problems.
Tom