Wil,
Two things...
It acts like a low voltage indicator. It's operated by the alternator control unit (voltage regulator) so you may have something going on there...However, my parts books are at the hangar. I'll post the number in the morning unless someone beats me to the punch. I'm pretty sure you'll have to change the assembly. Again, inexpensive, and if you don't tell anyone, you can do it yourself. That is, if you can butt-splice two wires together.