Are you referring to one that has three terminals on the voltage regulator or one that has the case drilled with a probe that senses the stator coils?
Bob, both alternators are rebuilt and installed, one on my Carryall and one on my M37. My other 4B's with alternators do not have the Tach terminal. The 'R' was the letter by the stud coming out the back of the alternator. Once you mentioned R, That was the leter, does the R explain where its hooked internally ? Unless i have a Alternator go bad, I hope to never open these ha ha haHey Paul,
How about posting a couple of pictures of the inside and outside of the case whenever you open them up. I am familiar with the "R" terminal on the voltage regulator but not what you are describing. I would like to see if the probe is a coil or if it goes to an internal connection. Thanks.