Alternator? belts?

[royg]

I have a m998 with a 6.2 engine and 3 speed trans. It sat unused during the winter and I'm just getting it out & about for spring. It starts great/runs good.

But driving around it occasionally starts squealing/screaming. If you let off the pedal and coast it goes quiet.

I thought it might be the power steering pump running out of fluid/cavitating. It was a bit low, I topped it off, but the noise came back a few days latter so I'm thinking a misdirect.

Last time it screamed I noticed the voltage guage went past green, past red to maxed out.

So now I'm thinking alterator. I could understand if there was some increased amp draw it could increase the torque required to drive it and it causes the belts to squeal.

Voltage regulator failing? But why would that be intermittent and cease if you let off the pedal and coast?

It only has a 60 amp alternator but the truck is bare, no stereo or extra lights.

Thank you for your thoughts.

 

[Mogman]

60A alternators are notorious for regulator failures, many times going wide open.

 

[papakb]

If your alternator goes full bore it'll boil the electrolyte out of the batteries. Keep a close eye on the voltmeter and if it goes outside the green zone do not run the truck any longer than necessary. Regulators are usually available on Evay and relatively easy to replace. Make sure to blow out any carbon dust in the cavity and make sure your brushes and brush springs are good. You can also buy new regulators directlt from Southern Automotive, the current manufacturer.