It sounds like you've got the multimeter set on the wrong voltage scale. It needs to be on "DC Volts", indicated by a "V" with a dashed line under it. If the symbol is a V with a curved line under it like a lazy "S", you're on the AC volts scale and you'll get exactly the reading you describe, a randomly changing set of meaningless numbers. I like the old-style "analog" meters, the ones with a sweep needle, not a digital readout, for working on generator-equipped vehicles. Digital meters simply respond to voltage and current changes too quickly, and the old DC generators and vibrating-point regulators have a tremendous amount of fairly low-frequency voltage spikes that get a digital meter very confused!
Jerry

Last edited by Hotrod Lincoln; 12/29/2013 5:40 PM.
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