just noticed on my 93 318is it isnt putting out enough voltage. when the car is off it shows 12.6 but after I start it, it only shows 13.10 and max I noticed 13.30. even sometimes when the engine is running it would go under 13 volts. I took the alt already 2 times and had it checked at an auto parts store, shows up as good. checked the belt, good also. at night the cluster lights are dimmed also:confused: