Squealing altenator

[pmsmechanic]

What concerns me is your statement about the rpm jumping, which is not typical.

If the tach is run off of the alternator then this would be possible.

 

[Agvg]

Quite common to use the alternator to messure rpm, in the Bosch world this connection is marked with a W.

 

[JRobyn]

I also once had strange "length" issues with a tractor fan/waterpump/alternator belt. For its first couple hundred hours, my Kubota belt stayed nice and snug. Then suddenly, I found it extremely loose, so much so that I had to adjust the alternator almost to the end of its travel. It's like the belt suddenly stretched by a HUGE amount. It's been ok since and hasn't stretched more.

 

[BHD]

Got a old 1980 fort pick up and it does the same thing squeals the belt on startup the belt is tight, and was adjusted with a belt tension gauge,

I just keep the RPM low, for a min or two, as the battery is recharged after the starting drain on it is relieved,