Hey guys I have a problem, about three weeks ago I replaced the battery on my 2000 ES300 because I had left the car off for two days and went to turn the car on and the starter made a loud tapping noise. So I had my dad come over and give me a jump and the car started up fine. So I went and bought a new battery thinking the battery was bad. So Today I went outside to start the car and the same problem happened battery was dead and I had to get the car jumped again. So now I dont really know whats wrong, do I have a bad ground somewhere is the alternator not working correctly I dont know. So if anyone has any idea what it could be or chime in I would really appreciate it thanks

 

in the first palce you should have had the charging system tested.

but now you have permanently damanged the replacement battery by draining it.

you could have the problems you mentioned. you can take it to a lot of places like advance auto which will test your charging system for FREE. naturally, you should alert them to the battery story you gave us. don't be at all shocked if you need yet another battery to go with , for example, a new alternator.

 

Agreed, possibly your altenator.
But I would take the battery back as soon as you get your main problem fixed and have it replaced under warranty. Just to be safe that is.

 

OK took the car to autozone to have the alternator tested and its only putting out 11.3 volts which is why I have been having these battery problems, Now I have a friend of mine that has a 2006 Highlander alternator with 130amps for $60 bucks and the alternator only has 6k miles on it so its pretty much brand new. Now I know it will bolt in to my car and I know the pulley and belt will fit fine, but what im not sure about is if I need a different harness. I read in the forums but there isnt really clear instructions if I need to get a different harness. From what I see it looks like its plug and play, bolt it in use my original harness and plug and turn that motor over and im ready to cruise down the highway. But if anyone here has a highlander alternator in there car let me know if im wrong.

 

When you state that you had the alternator checked could you please be more specific! Was it removed from the car? Did they just measure the output voltage? What? If they just measured the voltage at the battery then you need to make some more measurements. I have attached the schematic, there are several fuses that supply signals the the voltage regulator ( internal to the alternator ). If you do not verify these signals, replacing the alternator may not help anything.

As far as upgrading to a larger alternator, the main thing that you need to upgrade on the car is the output wire from the alternator to the battery, and the fuse link. The ground cable is already more than large enough ( it has to be to handle the load from the starter ).

 

They just measured the output voltage, could it be a bad fuse is that possible?

 

It could be as simple as the alternator warning light bulb being burned out. Does this light come on? Check the fuses indicated in the diagram.

 

Success 2004 Avalon alternator fit perfectly and works perfect in my 00ES and now the alternator puts out 13.9v my old one I pulled out and had it tested correctly and was only putting out 7.32v, now my car turns on great everytime and I let the car sit still for 2 days and it started right up, very happy with the results and o yeah the Avalon alternator puts out 100amps compared to the old alternator putting out 80amps a nice little upgrade

 

More alternator "upgrade" info for interested ES owners: https://www.clublexus.com/forums/es3...more-info.html