My car was parked, but running, this morning and it was just fine. i came out of the car to drop my son offf and come back to hear the dreaded alternator whine. this is very weird how it just popped up out of no where while the car was running. mind you, i've had my system exactly like this for 2 years. it's not there when the car is off, it increases and decreases with engine acceleration/deceleration. i've checked my amp wiring and it SEEMS ok...but i don't think that would be it since i don't get the noise when the car is off. what do you think it is? how can i fix it?