1988 Ford Ranger replace alternator, new sound?

[SolusUmbra]

I replaced the alternator on my 1988 Ford Ranger 2.0L and now it sounds like a tea kettle. Wonder if anyone else can hear the whistle and know what it might be.
Link to my Reddit post that has a video https://www.reddit.com/r/MechanicAdvice/s/QL91hviZUA

 

[Rand]

well theoretically its the alternator? since it didnt do it before?

 

[Oillover]

Alternator or tensioner pulley are my guesses.

 

[ripcord]

Sounds like a bearing. Take the belt off and spin and rock back and forth everything that's spin-y that the belt goes around. If anything makes noise or has noticeable play, that's probably your issue. Could be an air conditioner clutch pulley or water pump bearing in addition to what's been mentioned.

 

[SolusUmbra]

Alternator or tensioner pulley are my guesses.

My alternator is my pulley

 

[SolusUmbra]

Sounds like a bearing. Take the belt off and spin and rock back and forth everything that's spin-y that the belt goes around. If anything makes noise or has noticeable play, that's probably your issue. Could be an air conditioner clutch pulley or water pump bearing in addition to what's been mentioned.

Truck doesn’t have ac, water pump was checked and was fine

 

[SolusUmbra]

Alternator or tensioner pulley are my guesses.

Mechanic checked my new alternator and said it was fine

 

[kschachn]

Post a video from under the hood, please.

 

[RooflessVW]

Get a stethoscope. Should find it pretty quickly.

 

[Oillover]

My alternator is my pulley

Sorry, I meant idler pulley
It looks like this:

Rock auto has a few options listed for that engine:

 

[ka9mnx]

Post a video from under the hood, please.

I cant hear it with all the other noise and distractions going on!

 

[JavierH19]

Why record from the cabin if you suspect it's the alternator? You can pull the throttle cable from under the hood in that older ranger. My old 2000 ranger had a cable throttle but I think it went away once they went to the mazda engine soon after. I wish electronic throttle bodies still had a mechanism so you can rev an engine from under the hood to check for issues only findable at higher speeds without needing a helper.