IF YOUR VOLTAGE REGULATOR IS SUSPECT REPLACE IT. IT'S CHEAP AND EASY!
DIDN'T NOTICE YOUR LOCATION BUT IN OUR LOCATION (CAL. HIGH DESERT) WE SEE A LOT OF DISCHARGED BATTERYS FROM EXCESSIVE CURRENT DRAW FROM A/C SYSTEMS.
A/C BLOWER 28 AMPS
CLUTCH 8 AMPS
AUX. FAN 25 AMPS
ON THE LONG RUN YOUR ALT. WOULDN'T KEEP UP!
MF