Why do the lights dim at lower rpm?
Why do the lights dim at lower rpm? Dimming lights at lower RPM usually signify a bad alternator. Don't know about the replacement though. I have a 98 GST and the original Battery finally bit the dust a couple months ago (after a few jumpstarts). Replaced it with a nice new one, and now I've noticed that when idling, the lights seem to dim a bit. What happens if you have a bad alternator in your car? The car won't start at all. If the problem is a bad alternator, your car will slowly lose power. You'll be driving down...