A DIGITAL METER does not have a fast enough sampling (refresh) rate to capture ripple peaks. This comes from experience not hypothesis. A .5 ripple proves nothing with the rectified WYE type modern alternators (8 rectifiers) example: Ford, 3, 4, 6G models. Lose the 2.2uf capacitor within the alternator and that .5 ripple limit will have you purchasing an alternator. ND, Mitsubishi, Delco - all he newer (read motorhome) alternators except for "some" Delphi models are 8 rectifier alternators.
The test is incredibly easy to perform
The meter is incredibly inexpensive
The meter is incredibly easy to wire with 2 little wires and two strong alligator clips.
THERE IS NO CONNECTION POLARITY TO OBSERVE. You cannot connect it "backwards"
Connect meter to alternator output stud and to chassis negative (ground) start engine. If that needle swings upward off of zero you have a problem. I suggest SAMPLING some good alternators and get a feel for this critter if you are unsure or have doubts about testing efficacy. The analog meter test is virtually foolproof.
