I accidentally acquired several new voltage regulators in chasing down a charging problem. Currently I have been working with a pair of regulators one which will fry the battery at an even 16 volts, and the other that seems to settle for closer to say 10 volts. I can gather a bunch together and sort, but wonder about whether this is in any way normal? Also, can I take the relay board out of the equation by simply pluging the regulator into the wire from the alternator. I'm confused at this point.

The 16V one is fried, commanding full output from the alternator.

The 10V one is probably bad as well, but not quite the same failure mode.

If you just plug in to the alternator harness, you won't get the warning light so the alternator will never start to charge.

--DD