Overcharging Battery - Honda Civic 1981 (yes, '81)

There are 147K original miles on this car. I’ve been through 3 alternators, 1 voltage regulator, and 3 batteries -I’m beginning to see a pattern here.

I just had to put a new battery put in and they tested it to find the alternator was overcharging the battery. Then he hooked up a new voltage regulator to it and the situation didn’t change.

My question: There is a little thimble cylinder that is attached to the voltage regulator that has never been changed. I think it might be a resistor(?). Does anybody know what this little thing is and if it might be the answer to the overcharging problem.

Thanks for your input. I always get great help from Click and Clack Fans.

Sounds like a capacitor. It is probably not related to your problem, but it is certainly due to be replaced. If you’ve replaced the voltage regulator more than once, then it is probably a wiring issue. (If you’ve only done it once, maybe you got a bad one?)

Those old style regulators are adjustable. First remove the cover. There is a spring on each of the relays that’s attached to a metal tab. You bend the tab slightly to adjust the voltage. Which tab to adjust? Monitor the voltage and gently press each tab with your thumb. When you press the right tab the voltage will vary. Adjust it for 14.0-14.5V at fast idle and no accessories on. I haven’t done that since I had my '75 Civic.