Belt noise
 

hey guys got what I think is an alternator problem, boat is a 86 Avanti 22 with a 5.7 350 Merc, replaced both belts and I am still getting a squealing noise from what I think is the alternator.

When you go to put the boat on plane, it will happen when the volt gauge is maxed out at 18, sometimes if you let it idle the volts drop to normal and then you can run it fine, but you have to watch the gauge because if it maxes out the belt will squeal, the alternator belt was the one I blew which led me to replace both.

Any Ideas, Im thinking I need an alternator

sounds like regulator, probably time for bigger alternator anyway.

Common problem when the diode bridge goes bad, the alternator is going to full charge and not regulating the current. Get it rebuilt or swap it out.

Ok, I am going to replace, both the regulator and alternator. Why would it make the belt squeal tho, any ideas?

Bringing this thread back up. I put a new altrnator on the boat back in 2012. It ran good for the rest of the season, ran good last year. Now when I use my trim Im getting the same squeal when I go up or down with the outdrive. I ususaly have to return back to neutral, then go back into gear and it will stop. Any Ideas