can my voltage reg in my alternator drain my battery
I wouldn't think so , usually alternators will stop working never heard of a bad one draining the batt. What exactly is going on ?
yes, It could be possible if one of the internal diodes failed short and started drawing current from battery when car parked overnight also bad/faulty starter solenoid could draw current as well . Do a Battery Drain Test to verify At-fault electrical circuit drawing down your battery current. thanks.