Alternator with a mind of its own

[Highbanked Hauler]

  Went to a local  50 mile cruise in today and on the way I noticed the volt meter was jumping between 10-14 volts. To add to it the fan belt would scream occasionally. I checked the alt. bolt with a hand held meter and got the same readings. Its four years old with 1000 miles on it at the most and has been fine till today. It is a dual field alt. and one field is grounded. The regulator is a blue MP. unit and the battery is new this summer. Not sure of the alt. rating output. Ideas ??

[resq302]

I'd start by checking that all of the grounds are good.

[Highbanked Hauler]

I'd start by checking that all of the grounds are good.

    Yep done already, today I tapped it with a hammer while running, don't know if it did anything but took a short drive and was good so far.