It's amazing that we have any of the old trucks to restore, modify, and/or just tinker with. If all the purveyors of doom and gloom were even partially correct, there wouldn't be any of them left to work on- - - - -they would all have burnt to a crisp decades ago- - - - -torched by those pesky ammeters. The real reason they're not popular is the inability of the average hotrodder/restorer to understand what they're all about, and how to wire them properly to be safe and efficient. If somebody actually understood DC electrical systems and lead/acid batteries, he would insist on having not only a voltmeter, but also an ammeter, and most likely some method of monitoring the specific gravity of the battery acid. Very few professional mechanics, and virtually no average drivers have the knowledge and/or experience to properly interpret what a dash gauge is telling them, no matter if it's an ammeter or a voltmeter.
Just my opinion, supported by 60+ years of getting paid to fix cars, trucks, boats, and airplanes, and 30+ years of teaching the trade- - - - -but what do I know?
Jerry
