Technical New alternator already squeaking

[Burrows123]

Got a new alternator and belt fitted last Monday so been on a week and a day now and in the past few days every time i start the car it makes a horrible squeaking noise and gets worse as the revs get higher, people told me to loosen the belt and I do that but the battery will just die every time. So I'm having to drive around with this really loud horrible squeaking noise and it's sending me insane somebody please help as I don't think it's the actual belt that is squeaking I think it is the alternator itself?

 

[cmosfxx]

There is no a/c right?

Remove the belt and check alternator pulley. Turn it by hand, should be very easy.

 

[Andy Monty]

Did you spend the extra £4 on a new belt?

it could be that the new alternator is buggered,

or the belt is old and hard

or the belt is too slack

or there's a high resistance path to ground

or its the wrong alternator

or the battery is buggered...


also did you get the updated scuttle drain fitted as the original GP drain dumps water straight onto the alternator if parked slightly nose down eg on a hill / driveway

 

[Burrows123]

There is no a/c right?

Remove the belt and check alternator pulley. Turn it by hand, should be very easy.

I have tried that and tbh didn't feel very easy to spin round :/

 

[Burrows123]

Did you spend the extra £4 on a new belt?



it could be that the new alternator is buggered,



or the belt is old and hard



or the belt is too slack



or there's a high resistance path to ground



or its the wrong alternator



or the battery is buggered...





also did you get the updated scuttle drain fitted as the original GP drain dumps water straight onto the alternator if parked slightly nose down eg on a hill / driveway

I had a new belt fitted aswell car doesn't have a/c tried to loosen the belt however the alternator won't work and the battery doesn't charge.

 

[Andy Monty]

If its slipping it needs tightening not slackening

 

[portland_bill]

Is this a squeak, coming from a worn alternator, a squeak from an overtight belt, or a squeal (scream) from a slipping belt?

If the alternator is difficult to turn, this suggest there might be something wrong inside. Call into the supplier and ask them to have a look.

If the belt is squeaking due to being too tight, that is easily remedied, but this, and an internal squeak are unlikely to be particularly audible outside the car, only when listening with the bonnet up.

If the belt is squealing, this suggests it is slack, the demand is too great, or the pulleys are polished.
Slack - retension it.
Demand too great - battery dead, or alternator is tight. Alternator should spin freely when belt disconnected. Any resistance suggests something rubbing inside, or bearings failing.
Pulleys polished - more common that you'd want. When belts wear, and become slack, people ignore them until they squeal. If that is not dealt with, new or retensioned belt, the slipping belt will polish the pulley surfaces. Any replacement belt can struggle to grip the polished pulleys. The cure is new pulleys. The running surfaces can be dressed with very fine abrasive, but this is a difficult job on the old single groove pulleys, a nightmare on the multi-groove ones. A Saturday afternoon at the kitchen table may beckon.