Omc 5.0 cobra alternator making weird noise

[Nikokrzynowek]

Hey guys, I’m having a weird issue with my boat. I finally fixed my trim pump so I can trim up and down, now anytime the boat is running and I trim up or down there’s a loud squealing coming from the engine compartment. As soon as I let off the switch she squeezing stays for a good minute. I just bought a brand new 12v 55amp alt for the boat, and brand new belts. Not sure if that’s not enough amps to run it or it’s getting frozen. If it is a alternator, can I saw a 160amp 3g alternator in there?

 

[vasy]

Check what is making a noise.
I got 85 amp for mine and works fine.
You can remove belts one at a time and see what's up, boat should be able to run without alternator for a bit, just on battery.

You can have anything from wrong belt tensioner to a crappy new alternator, to not enough amps.
You can check amp draw if you have a clamp meter or any other amp measuring device.

 

[Nikokrzynowek]

I can’t tell if it’s coming from the alt or the belt. The alternator belt isn’t destroyed at all and has never given me an issue I’ve had the boat on the water at least 20 times this year (with no trim). And now that I finally can use the trim it’s making this god awful noice. And was also smoking too. Yet again no belt smell. Belts not hot and doesn’t look to be in bad shape at all

 

[vasy]

You can make sure the belt is the right tension and maybe spray like 10w40 or belt dressing on it and see if the noise goes away, if it does, it is the belt and you can just get a new one, maybe better brand.
I got one brand (Dayco) , was noisy at load after just 10 trips... the new one I got is much better. (AcDelco)