Re: If My Rectifier/Regulator Is DOA--
Its impossible to give you a definite answer. There are 4 or more diodes in a rectifier and it depends on which one is bad and whether it is opened or shorted as to how it affects your tach. They are easy to test with a VOM and instructions are in your manual.
Thanks & i appreciate ya'lls time-
Guess its time to buy a new multi meter (mine died) & test it-
Reason i'm digressing is my rectifier is the high dollar ($200) one & my tach does all i mentioned in my opening post,

Dang thing is keeping my cranking battery charged (minimum) but never shows above 12.6 volts under use --