The damn thing lasted for a month, and then the same problem.
Again we took it out and got it under warrany at the shop. They said some diode burnt out. We got it back the next day, put it in, then it lasted for an hour.
When the RPM's are up the light stays out, its only when you're at a stop light and your brake lights are on and the RPM drops.
We could have bought a new alternator for less than what my dad paid to get this one rebuilt.
Since its still reliable, my dad is giving up.