AutoMac
Dave,The Automatic Alternator Control (AutoMac) is an earlier, manual version of today's multi-stage alternator regulator/controllers. It adjusts the field current going to the alternator, which controls the output. With the AutoMac, you "dial in" the amps you want the alternator to put out, and the AutoMac holds the output there. Without it, the alternator output will taper off very quickly, and it will take forever to recharge your batteries. Standard alternator regulators are designed for cars (high, short-term drain; long, gradual recharge). The AutoMac has some sort of voltage sensing, as it will cut out when the battery has absorbed all it can at the output you set it for, and go into a "float" mode. At that point you have to lower the output and turn it back on. My last boat had one, but that was over 10 years ago, so I'm kind of fuzzy on the details. You can either keep it and learn to manually monitor and adjust it, or take it out and replace it with a modern multi-stage regulator for a few hundred dollars. Good Luck.Tom Soko Julandra #659