RE: Charging System Diagram
How do you know the alt is good? Did you pull it off and test it? If you did, and it tested good, I'd buy a new voltage regulator and swap it out. They're known to go bad every now and again. It's the rectangular box bolted to the firewall right behind the engine, 2 bolts and an odd-shaped wire connector. Not as many shops can test those as alternators, but it doesn't hurt to ask. They should run about $30 or so I think, maybe less.