Battery was dead the other day. Charged it up. Low charging voltage while running. And goes dead while sitting for a while.

Not real familiar with externally regulated alternators.

 

If you have a question it may help to say what you are working on so folks can give accurate information for your vehicle.

 

71 Cutlass with 455
HEI ignition
No radio/ac/power windows or locks

Full field on regulator only nets 12.6 Volts

 

Is the charge light on? If you charge the battery to 12.6 and let it sit not connected to anything, will it hold the charge? I've seen shorted batteries that can put a load on the system and you won't see the full charging voltage.

 

Basic troubleshooting...start simple....Check all Grounds and other connections. Clean and inspect both ends of both battery cables. Load test the battery.

Verify what alternator you have before we go any farther. Note the numbers on it and snap a pic or two showing the rear and/or side connections

 

If the battery's over 8 years old, there's no sense in going further with diagnosis, until it's replaced

 

Battery about 6 months old. But I did charge it unhooked last night and I’ll check it this morning, as I was leaning towards it giving problems. Will update.

 

Sometimes newer batteries fail, depending from where they're imported

 

Battery held. 1.7amp draw with everything hooked up. 0 amp with either alternator or regulator unhooked.

Alternator got slightly warm while battery charger was hooked up. Found that odd, but not sure. Never paid attention to any other vehicles before.

 

With the engine off and all accessories off there shouldn't be nearly that high of a current draw. If unplugging the alternator stops the draw then it sounds like there is a bad diode or a leakage in the alternator.

Good luck!!!

 

Thanks! I’ll entertain swapping to an internally regulated unit at the same time.