I replaced my alternator several months ago with a new Napa unit, but it whined a lot. I returned the alt and went home with another new one, but found it was assembled wrong (the back was clocked 180 degrees off) and the cables would not reach, so off I went to Napa again but the only other new one in stock was also assembled wrong. They said if I or they re-assembled them, the warranty would be voided. So I took home a rebuilt one with lifetime warranty. It still whined, but not as much. After a few months, I got tired of the whine and decided to use the warranty and try another one. You guessed it, it whines more than the first one.

Has anyone else had a similar problem? Have you used a replacement one with good results? I have also tried swapping an old fan belt and new one and neither changed anything.

Thanks,
Chris

 

Are you talking about whine where you hear it through the radio? or is this an under the hood sound? Mine whines through the radio but thats because I have the amp power cables running along with the rca's. I fixed it once, then added another amp and now it's back.

 

Usually a whine in the alternator is cause by the belt slipping!! Try replacing your belt and see if it does the trick. If not you can always return the belt

 

The whine is comming from the alt, not the radio. It whines with both the old belt and a brand new one from Napa. It is consistant and gets louder/higher with RPM. I have had several people ask if I have a blower on it!

The belt appears to be tracking fine. When I took the last two alternators off, you could hear a slight scraping when you spun the alt pulley by hand so Napa did not have any problem taking them back.

 

Hmmmmm, I'm running out of ideas...have you tried getting an alternator from a different shop??? Have you tried a different brand of alernator??

 

No, I have not tried another brand. Another brand would mean buying a new one. I was hoping someone else has experienced this before. I would not mind trying another, but wanted to exhaust all other options first. I have tried one new and two rebuilds and have a hard time thinking they were all bad. I have never had any problems with Napa parts in the past.

Guess I am hoping someone will chime in and tell me I overlooked something or they had the same problem.

 

Are you sure it's the alternator and not the tensioner or ps pump? If it is the alternator, I'd check out G&R auto parts (google em). They have factory take off parts fairly cheap. Personally, I've had alot of bad luck with aftermarket electrical parts...it's possible that the bearing in the alternator is bad and is a direct result of poor remanufacturing.

 

How about trying a new alternator pulley? Another thought- are the belts those ones with notches on the inside?

 

I went w/ a used(only 5000 miles on it) 145A off of ebay works like a charm.

 

The whine started with the alternator change. The original one was not switching properly when I let off the gas. The headlights would flick off when I let off the gas. The swap fixed that problem, but is now whining. I noticed the idler pulley next to the alt had worn the paint off one side (approx 90 degrees only), not evenly all the way around as you would expect. Sooo, I switched it out for a new Napa one, and that did not solve the whine either.

There is a noticable difference as I switch from one alt to the next, so I am pretty sure it is the alt. It may be another component, but i am not sure how to check. I spun all the pulleys I was able last time I had the belt off, but noticed nothing, except the one idler I changed had a slight rubbing sound, but a new idler did not solve the whine (although the idler probably needed to be replaced).