Duster Amp meter

Whether you do it the MAD way or not please READ the article as it details the why and how of the failure. There are several failure points in these cars "in general"

1...the bulkhead connector. Those terminals were NEVER designed for the high current of charging. Even at nominal 20A these connectors routinely fail in such uses as electric furnaces!!

2...The terminals on the wires at the ammeter can fail
3...The entire ammeter structure is poor. Typically, the alternator studs are "sandwiched" between the ammeter shunt, the insulating washers, on some years a PLASTIC cluster housing, and the nuts. If ANY of that starts to get loose, then it heats and causes complete failure. Seen MANY of these with driving lights, snowplows, or winches on pickups

4...In a few rare cases the "welded splice" which is in the black ammeter wire up under the dash has failed. I've lost count, but in my lifetime, I've eitiher seen or been privvy to about 10 of these failures now.

"For good measure"

5...In other related cases, the fuse clips become old and corroded in the fuse box

6...The headlight switch can become overheated and damaged connector/ terminals/ switch

7....The ignition switch connector, the switch itself internally, and the "ignition run" wire going through the bulkhead terminals causes voltage drop and OVER CHARGING

There are of course other problems!!!! LOL