Devbot
New member
Hey all. Today my alternator decided to quit after I got to work - batt light came on so I took a multimeter to it and would not charge above 12.09A. No big deal, the Toyota dealership down the road had a "new" Denso reman in stock. I was told it was brand new over the phone, not a reman, but I didn't really have a choice but to install it; I live 20 miles away and my work was broken into twice last week, so I'd really rather not leave my car there.
Well I put on the alternator, and the battery light went away... but after maybe 5 minutes of idling it began producing a very high pitched whine - I mean seriously on par with a dog whistle. I thought it was a vacuum leak coming from the air box, but it's clear as day 100% coming from the alternator. It's not deafening but can certainly be heard over the engine and radio. Reacts immediately to electrical load or engine speed, and only cuts out when dipping below 1000rpm.
Will this go away with time, or did I just waste $300? Is there a fix for it besides buying another alternator? It is ungodly annoying and quite embarrassing; I turned a lot of heads on my way home. I've never heard an alternator make such a noise and have no idea what's the cause or how to tackle it, and of course information is apparently scarce beyond 10 year old posts going "yep I had that problem once" with no resolution. I read somewhere that it's due to the alternator trying to send too much voltage or something, but I can't see how that is if it's an OEM reman? Unless Toyota doesnt know what the hell they're doing. Again, never before heard this so I'm at a total loss :shrug:
Edit: now I see why everyone does a CS144, it's practically the only solid option under $200
Well I put on the alternator, and the battery light went away... but after maybe 5 minutes of idling it began producing a very high pitched whine - I mean seriously on par with a dog whistle. I thought it was a vacuum leak coming from the air box, but it's clear as day 100% coming from the alternator. It's not deafening but can certainly be heard over the engine and radio. Reacts immediately to electrical load or engine speed, and only cuts out when dipping below 1000rpm.
Will this go away with time, or did I just waste $300? Is there a fix for it besides buying another alternator? It is ungodly annoying and quite embarrassing; I turned a lot of heads on my way home. I've never heard an alternator make such a noise and have no idea what's the cause or how to tackle it, and of course information is apparently scarce beyond 10 year old posts going "yep I had that problem once" with no resolution. I read somewhere that it's due to the alternator trying to send too much voltage or something, but I can't see how that is if it's an OEM reman? Unless Toyota doesnt know what the hell they're doing. Again, never before heard this so I'm at a total loss :shrug:
Edit: now I see why everyone does a CS144, it's practically the only solid option under $200
Last edited: