I don't think that will work -- but I have never tried it, so I really don't know.
But if it was that easy, why would Tuff Stuff go to the trouble of putting this in the instructions for its 1-wire alternator?
NO WARNING LIGHT
Note that a 1-wire alternator does NOT permit the use of a charge
warning (idiot) light. Most hot rodders and muscle car enthusiasts
prefer the use of a volt meter or ammeter to monitor charging.
However, certain Tuff Stuff alternators like the 7127, 7139 and
7140 series have terminals that may be used for a warning light.
To wire a warning light using one of these alternators, simply
remove the terminal plug cover and connect the R (Left terminal,
looking from the back of the alternator) to the warning light wire.
https://www.tuffstuffperformance.com...structions.pdf
and PowerMaster says the same thing about theirs:
https://www.powermastermotorsports.com/001___IS_ALT.pdf