Well, having just completed a problem free 2400 mile road trip just a week or so ago in the 2003 ES300 I was about to start a 400 mile round tripper up to the Kansas City area. Got the car all loaded, started it up, backed it out of the garage and I noticed the charging system warning light was on. I checked a few basic things and decided to switch cars. Threw everything into a 2005 Corolla and off we went.
Got home yesterday, put a charger on the Lexus battery and brought the 2 year old battery up to full charge. Checked the voltage with a multi meter (after letting the surface charge drain off) and it leveled off at 12.6 volts. Started the car up, reconnected the multi meter and still read 12.6 volts. Revved it up and no change. I checked different points on the alternator and different ground points with the mm on the engine and it still read 12.6v and was now starting to drop.
So, the alternator is shot. Not a surprise as it's the original on a 20 y/o car with 378k miles.
Now the question: As far as I can tell at different Lexus sites, either the 27060-20240 or the 27060-20230 will work. Both fit the same year build as my vehicle and both are 100 amp alternators. I've read on this site that a Lexus RX alternator or a Highlander alternator can be used but I cannot find the exact part number for either one of those so I can compare prices on a rebuilt Denso at RockAuto.
Can anyone supply me with those part numbers?
Thanks.

 

Hello,

Highlander alternators are only mandatory in previous generation ES300, as those came with just 80A output from the factory, which was barely sufficient. In your case, a 4th-gen ES already comes with a 100A alternator, so any Denso rebuilt alternator that fits your car will work, RockAuto sells those here is a link to the one for your car, though you can look around other 1MZ/3MZ cars after 2002 for a cheaper option.

Hope this helps and best of luck!

 

27060-20230 was original part number
then 27060-20240 ( current #) superseded (replaces) the original #

My original one died recently (286,000 miles). Installed denso reman from rock auto - so far so good.

 

Hey Arsenii! Thanks for the reply. I wondered if that might be the case (2003 already has 100 amp alt) so thanks for verifying. I did some scouting around the net and couldn't find any other vehicles that use the Denso 2101214. I'm sure they're out there, I just couldn't find em. I did see that alternator in the link that you sent. And of course, it's the most expensive one they offer. Ugh. But, my luck with Denso remans has been very good so I'll bite the bullet. Thanks again.

 

Fortitude: Thanks for clearing up my confusion on the part numbers. Much appreciated.