Alternator acting up

[atc82]

Over the past week or so, a winding (?? thats the best way i can describe it)sound has become more noticeable from the engine. The sound goes up increasing rpm's. I popped the hood and it sounded like it was coming from the alternator from what I could tell. When just ideling, and I flip the lights on, the volts drop quite a bit. Also, when i turn the blinker on the volts take a dip. The sound was very noticeable today as I could hear it with the radio on. I am supposed to take a trip to Oklahoma City this weekend, but now I don't think i am going. Has anyone else experienced this sound that I am talking about? Is it time for a new alternator? Any ideas?

 

[manitoufs]

Sure sounds like it. Even if you haven't done anything like this before, you should be able to change it out in less than an hour. Just make sure you disconnect the battery. (Keeps you from getting big sparks when you are working in the area.)

You may want to take this opportunity to upgrade to a 140a. If you have time, you could find a local rebuilder and ask him to do your core with the upgrade. You should have him put an overdrive pulley on it also. I had one rebuilt for about $75.00.

Be sure to have a fully charged battery before you try to start the truck after you install the new alternator. You don't want to put a huge load on the alternator.

 

[atc82]

I was looking at the alternator after I had shut the vehicle off and noticed lots of little hairline cracks in the belt. Is this normal? I figure might as well replace it since I will have the alternator off anyway.

 

[GM TURBO]

I had mine make funny noises like that - and shortly after the bearings locked up - that was fun. The next one broke the alt pulley - that was fun too.

The serpentine belt will have some cracking - kinda normal - but you are gonna have to remove it (kinda) to replace the alternator - so for 30 bucks you could just replace the belt as well. I have seen serp belts get pretty shredded before they go (actually never seen one break) but it is a good piece of mind to replace it.

 

[InvisiBill]

I had two alternators go on my 4.3 S-10. The first time the rear bearing siezed up. The second one actually caught on fire, and the fan crashed down into the bracket. When I tossed it on the counter where I bought it (complete with the roadside dirt I used to put the fire out), they told me they had the exact same alternator with a heavy duty rear bearing. No problems since then...

Jegs or Summit or JC Whitney sells an "Iceberg" rebuild kit. It has a heavy duty rear bearing and some fancy housing that's supposed to cool better. You can also get one version that comes with different internals to put out 140A. I'm not sure if I've ever checked and made sure it will work with our alternators though. Anybody know for sure one way or the other?

 

[atc82]

I had it tested at AutoZone today and its a little weak, but the bearing is making all kinds of noise. The guy that tested it actually new what a Syclone was. I was shocked. They have a Duralast 105 amp and an AC-Delco 105 amp. Which one is better or are they they same? Thanks.

 

[manitoufs]

140a if you can find a rebuilder. You won't be sorry. Don't forget the overdrive pulley

 

[SyTyJedi]

Aaron we'll get that alternator swapped out tomorrow - I would pick the AC Delco one.

If any of you get the overdrive pulley - also don't forget that you will need a shorter belt.

 

[manitoufs]

I beg to differ on the shorter belt. If your tensioner is ok you should have no problem with the stock belt. If you are seeing cracks in your current one - be sure to replace it.

 

[audiophile]

A similar problem happened to me. But instead of a span of a few weeks, mine was a span of 15 minutes. I was leaving town with a slight wirr from my engine. While about 3/4 of the way home, it was dreadfully loud. My amps dropped to near zerop and i pulled over. Glad I was in front of a friend's house, because I needed a fire extinguisher. There was some pieces of alternator blades in my hood fire blanket. They couldn't rebuild my alternator core. So I got a 140 amp. My lights dont dim now when bass hits.

-Burns