gs400tx

only putting out 12volts. Killed one battery that was 9months old.
Idling very slow... about 300 in gear.

gs400tx

611 for the alternator,
60bucks for core and tax.
Total to install 822...


I might replace that thing myself afterall... 208 with a 100 dollar core sounds much better than 822.

Anybody know what its like to get at? I had a quick look (before i heard 822).. and it looked kind of buried.. but.. i will dig if it involves 600+ bucks.

i found a local alt-company that will rebuild that one for 320 counting removal and reinstall. Extra ten bucks and they will lifetime warrenty it...
hmm.... sounds like a nobrainer.

gs400tx

Bad voltage reg... likely cause according to the alt shop was a bad battery. But,, the battery was replaced on Sunday and they said the bad cell was likely caused by a bad alternator..

Sound like a chicken and egg thing to anybody?

BananaGS

with the engine is running (idle), you should have at least 13.2V at the battery, else your alt is bad.

want to test the alternator? (not the very best way) but the easiest way it to un-hook the battery cable (+ or -) while the car is idling, if the engine die, the alternator is bad, else, you alternator may still work fine or work at maginal level, that will need to use a voltmeter to tell.

Check the battery cable connection, are you sure you get good connection (good power to the battery)?
That is another cause of dead battery

DPGS430

My alternator was history @ 30k in my 01 GS430

Warranty

Guru

Mine's officially dead as of today too. It's been acting funny all week lights dimming etc. . .
I was stupid in not taking it in but have been swamped with work. GUess tomorrow is new battery and alternator day.

jtanoyo1

I also had a similar problem. I left the car for a week without being started up when I went to Europe on a biz trip and when I tried to start it up, it doesn't take its usual speed. Almost like a semi-dead battery. I didn't think much of it because I thought it was probably caused by the fact that I left it sitting for a week.

However, 2 days ago, the same thing happened and this time I just used the car the night before!! Slow turning on, lights on speedometer dims momentarily as the car tried to start itself, then finally it starts just fine. Is this a busted battery or alternator? Help!

Guru

I may have other issues other than the alternator. I'm trying to get Lexus to cover the alternator and hopefully any other damage it may have caused in the process of dying. I don't think my ECU is getting power now either and I checked the fuses. Maybe there's a relay I'm missing or something. 61,000 miles should not be enough time to kill an alternator and of course they are telling me it's not covered under the powertrain warranty.

gserep1

Hello,
I have been following the posts about this alternator testing, and I can tell you that the advice to remove the battery cable while the engine is running is a very BAD idea.

The reasons are:
1. The alternator needs the battery voltage and current to keep the system regulated. If your battery is low, the voltage regulator will sense it, and increase the current to keep up. This extra current is what causes alternators to burn up. The alternator supplies all the current to run the accessories once the car is running, so the extra current will take it out.

2.Removing the battery cable while running tells the voltage regulator that no current or voltage is reaching the battery, and it is the same as saying "0" volts, so the alternator compensates by raing voltage to as high as 17 to 20 volts.

3. This 17 to 20 volts will scorch the various computers in the car, (including the ECU, transmission modules, ABS, air bag module, and many others. The potential for damaged components is enormous.

Always have your el;ectrical system checked using electronic testing equipment by trained technicians

Just a word to the wise,

(I say it from 32 years experience working military ground support equipment and civilian automobiles).
Been there, done that, and I damaged a lot of equipment over the years. It is not worth taking a shortcut.

NUFF SAID

jucee187

how about if you have a digital capacitor that displays the voltage? is that a good "test" of your charging system?

when the car is on and idling it reads between 13.5 - 13.9 or sometimes 14.0-1...

what kind of voltage numbers are these?

Thanks

theanimala

I posted in the main forum about getting stranded by my GS this past week in the blizzard. Ended up being the alternator. Just had my local lexus dealer replace it, as well as a new battery with a 5 year warranty, for $729 before tax. Sounds like your dealer is really ripping you off... (and I thought mine was bad)