So.. to paraphrase:
Your light is irratic.
WHEN your light is on, you still have 14.2 volts.. even if you rev the car to a mid point? (3500, 4000?) (the revving part is imprortant..lol)
I can think of two things:
One: You haven't tried revving it while measuring with the light on. (it could be your belt slipping under load, or tensioner, etc.
Two: the connection that leads to the "idiot light" on the alternator is loose, and causing intermittant opens on that circuit, triggering the light even though you are charging fine.
Ray
