My alt light just started flickering and glowing while driving. It goes on solid sometimes at idle, and when I step on the brakes. It just started doing this recently, but it is still charging fine cause I have an ammeter connected to it, and it is still charging like it used to. Its an old style alt with a seperate regulator. Could it be the regulator going bad? I have a small underdrive pulley, and sometimes it would be on dim at idle, which is understandable, but now its on solid at idle. After it warms up, it goes away for a while but on long trips (more than 45 minutes) it comes back on. Any ideas/suggestions where to start?