reportedly some digital voltmeters are hard to get the numbers to settle down but if the amp gauge is swinging wildly then that definitely needs to be addressed/taken care of before considering an upgrades. We'll solve it & go from there. The MADD info is good if you don't mind losing your ammeter function (I do mind). I clean every terminal/connection and add a voltmeter to switched 12V & relay the headlights/heater/ac directly to the alt batt stud with relays & do Nachos bulkhead parallel bypass. the swinging ammeter sure sounds like a bad electromechanical reg or the alt. Keep us posted. Your batt is a good one right? EDIT had an ammeter that would go all the way to charge when I revved the end but came back to near 12 o'clock at idle/lower speed. it was the electronic reg. more info on WHEN it is wildly swinging (how far/which way)