JasonARGY

Hello.

Here is my current situation: Car has 165k and most likely on stock alternator. The other day, I was driving to class and heard a whine outside and battery light came on. I drove another 2 minutes or so until I parked and noticed the whine went with the RPMs and when I popped the hood I could smell burning. I went to class and 3 hours later, to my surprise, when I started the car, the whining noise only came on for 1 or 2 seconds and then went away and everything seemed to work normal. Got home, checked voltage and at idle with seat warmers on, defrost, headlights, voltage was right at 14.0. I checked with the fancy secret Lexus screen and a volt meter at battery. Battery shows 12.6 off and is only about 6 months old.

What I think happened: From my research online, it seems like a diode went bad making that whine noise and while everything seems to be working fine in terms of voltage, the maximum current is most likely compromised. (I can't imagine the burning smell, noise and battery light weren't signs of something being permanently damaged)

My dilemma: I immediately went to parts store and ordered a Ultima unit. After doing a bunch of research, I am regretting this decision as it seems like these remanufactured pieces are hit or miss and some posts seem to indicate that "remanufactured" doesn't always mean the rectifier has been replaced, possibly putting me in the same situation I am in currently after replacement. The problem is that I am a college student living in an apartment and it snowed today. The last thing I want to do is replace a still working alternator with one that may not be better in a parking lot in freezing weather. What I think I want to do is cancel my order, get my money back and spend the extra $75 on the reman Denso unit from Amazon. My question is, if I keep a close eye on the voltage, is it dumb to rely on the car for short trips to the store and such while I wait for a dry day (I live in WA)? Also, are the Ultima parts really that risky or is it just a small percentage that fail? I ultimately want to get a rebuild kit and take on rebuilding the original Denso unit as I think I am comfortable enough with the process but not sure what to do with it after that haha.

Thanks in advance.

RA40

iTrader: (6)

My neighbor's bro-in-law is on his 4'th Ultima and I hear similar stories as well as online. The remanutfactured Denso is easily bought from Amazon or Rock Auto. If there is a reputable local rebuilder can call them too. The local rebuild shops to me use Chinese or Taiwan bearings, the diode and brush kits are China sourced as expected. The Denso I bought for the Corolla had a sticker on the outside with the American Flag and "Made in USA." Denso has plants all over so it may come from Mexico or China too.

Bocatrip

430

I trust Denso. Also, many auto parts stores today will test your alternator in the store parking lot for no charge. Auto Zone, Advance Auto and O'Reilly's come to mind in my area. Find one that performs the service and get it tested. The price is right.

JasonARGY

Thank you all for the recommendations. I went ahead and cancelled my O'reily order and got the Amazon Denso 0570 unit. Unfortunately, the weather went from dry mid 30 degree days to 25mph winds and rain. Luckily, the car still works as if there are no issues but I am scared to go more than 4 or 5 miles from home.
I might attempt to make a How-To with the rebuild for something to maybe put on my college resume but there seem to be plenty of guides online.

jimbosr1

i had mine rebuilt (factory one) a few years ago with Denso parts for $90 and its been operating fine.If there is a store that rebuilds near you, you should look into having it done.Usually takes a day or less if they are not busy.

911LE

I just rebuilt mine recently. https://www.clublexus.com/forums/ls-...r-rebuild.html

caddylover

i always get my starters and alternators rebuilt by a shop. Cheaper than going to the auto parts store and i know he's gone through it thoroughly. Have yet to have one fail again after he's rebuilt them.

Tom57

At that mileage, I'd replace the alternator as a preventative maintenance item. Replaced alternators in my '01 (twice - it has 297K on the clock) and one of my '06's, both with Denso reman. - 1 from Amazon and 1 from Rock Auto. (Note: The alternators are different in each.)

JasonARGY

That is a great guide! I will definitely use that. Where did you find the rebuild kit and diode assembly? I've looked through ebay and amazon and I'm having a hard time finding a rectifier but I think it is the one below?
Rectifier: https://www.ebay.com/itm/Alternator-...u~F9:rk:2:pf:0
Kit: https://www.ebay.com/itm/Alternator-Rebuild-Kit-for-2004-06-LS430-2006-07-GS430-Regulator-Brushes-Bearing/273048992418?fits=Year%3A2004%7CModel%3ALS430&epid=18014119041&hash=item3f92fcfaa2:g:QOgAAOSwMfhacdZq:rk:1f:0

I got my fresh reman. Denso unit I got from amazon sitting on my desk and hoping to get the install done tomorrow. While the voltage on my current alternator looks good, I am going to check the AC voltage before taking it out and comparing it to the new one. That should supposedly be different if the old one does in fact have a bad diode but we shall see.

911LE

I bought my rectifier from my local rebuilder. I also bought a kit online like the one you show but the brush holder assembly wasn't correct. The one in the link you posted doesn't look like the correct one. I ended up reusing my brushes as they were within spec, barely. To accurately diagnose an alternator you need to be able to read and measure well over 100 amps which most multimeters aren't capable of. You need voltage and amperage to charge a battery.

Johnhav430

My wife's went bad on her GM SUV last summer. Same symptoms as above, with maybe one exception. She got a message on dash that battery saver was active while running, very bad. The car had an extended warranty and so a "new" Denso was installed. I looked up the job and it was $1,100. I thought American cars were less costly to maintain?

From my experience with remanufactured starters, I cringe when it comes to remanufactured parts (2 of 3 went bad, 2nd right out of box). I am not equipped and I'm sure I'm not alone, but a Lexus corp tech told me always rebuild these items yourself, because you'll never get the same quality otherwise buying remanuf.

That's why I think with our cars if I needed a starter I will pay indie since if it fails, it's his labor under warranty...alternator not sure as I don't know the labor hours nor cost on the LS430

edit: should have stated cringe with remanufactured electrical parts--no problem imho with hydraulic...

Johnhav430

Where do you find these guys for the starters and alternators?...I can tell you I had an ABS pump rebuilt for $249 as the part costs about $3k, and they state they correct the mfg. defect that causes them to fail in the first place and have their own special procedure for carefully opening it where some others simply crack it open by force...been 2 1/2 yrs. no prob and it's warranted for 5....

JasonARGY

Well, weather cooperated with me and alternator install went well. Took my alternator apart and it looks like it may be toast since one of the copper rings on the shaft is a little too worn out for some reason. When I compare my pic to the one from 911LE's guide, I don't think I would feel comfortable replacing brushes and rectifier and putting this back in my car without somehow replacing the rings as well. Probably not worth putting money into at this point.




Edit: I think I also found the bad diode that probably went bad when I heard the noise from alternator, light came on and smelled like burning. All the diodes seem to have a reading on the diode settings on my multimeter and when leads are changed, the circuit shows as open. But one of the diodes has a small reading regardless of direction which as far as I understand, is an indicator of a bad diode.

911LE

That piece is junk. Looks like it ran for a long time with a completely worn out brush. That piece is replaceable as well and isn't too expensive.