I drive a 95 240sx 1 hour to work during the week. Randomly during the drive I'll hear a whinning noise and it gets higher/louder as the rpms go up. It won't stop until the next time you turn off the car. Also, when I hear the noise and shut off the car my clock gets reset and the radio spits out my cd just like it would if I unplugged the battery or took it out. Does anyone know what this is?? Sounds like an alternator problem to me. Thanks.

Karl