Alt going out, how long do I have?
#1
Pit Crew
Thread Starter
Alt going out, how long do I have?
99 LS400 220+ miles. Daughter's car. Replaced battery about three months ago and now the battery light is on. How long will a fairly new battery last with no alternator support? A week? 3 days? Anyone have experience? Will get it voltage tested tomorrow to confirm. Currently fluid everywhere as expected. Belt nice and tight.
Thanks in advance!
Thanks in advance!
#2
Could be minutes, hours, or days... no way to know. I suggest replacing the alternator ASAP and making sure the power steering pump isn't leaking, as the new alt will be destroyed quickly if so.
The following users liked this post:
pmarr (02-11-17)
The following users liked this post:
pmarr (02-11-17)
#5
Pole Position
The future is uncertain and the end is always near.
If replacing, go for higher efficiency 130A output alternator from 2001-2003 LS430...Same alternator connector...
It has a third mounting flange hole....buy that bolt and nut from Lexus.
check out my alternator posting on the subject
If replacing, go for higher efficiency 130A output alternator from 2001-2003 LS430...Same alternator connector...
It has a third mounting flange hole....buy that bolt and nut from Lexus.
check out my alternator posting on the subject
#7
Lexus Test Driver
iTrader: (1)
When the alternator went out in my '91, I only had half an hour of city driving before it died. So yes, plan for the worst.
Also, when it died, it did it right as I was driving. I shifted to neutral and conveniently coasted to a stop, parking at the curb. My lights, radio, everything optional was off.
When your battery is bad, once jump started you can run almost indefinitely on your alternator. When your alternator is bad, the battery will just drain out and you're done.
Also, when it died, it did it right as I was driving. I shifted to neutral and conveniently coasted to a stop, parking at the curb. My lights, radio, everything optional was off.
When your battery is bad, once jump started you can run almost indefinitely on your alternator. When your alternator is bad, the battery will just drain out and you're done.
Last edited by oldskewel; 02-12-17 at 10:44 AM.
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#9
Moderator
The future is uncertain and the end is always near.
If replacing, go for higher efficiency 130A output alternator from 2001-2003 LS430...Same alternator connector...
It has a third mounting flange hole....buy that bolt and nut from Lexus.
check out my alternator posting on the subject
If replacing, go for higher efficiency 130A output alternator from 2001-2003 LS430...Same alternator connector...
It has a third mounting flange hole....buy that bolt and nut from Lexus.
check out my alternator posting on the subject
The following users liked this post:
Scorchez (02-22-24)
#11
Pole Position
https://www.clublexus.com/forums/ls-1st-and-2nd-gen-1990-2000/807894-1998-2000-ls400-alternator-upgrade.html
some images of both alternators...I believe the increase from 100A to 130A was attributable to profile of windind wire 100A Alternator with 2 mounting ears
130A Alternator...(2001-2003 LS430 only has same harness alternator plug connector as LS400 )has 3rd mounting ear...but will bolt in with special bolt from LS430
Positive cable stud on LS400 Alternator..notice round wire.. LS430 postive cable mounting stud...
Notice the windings wire profile inside casing...appears to be more square (higher efficiency design) or perhaps reconfigured windings.
Image showing 1UZFE engine with stock alternator installed.
Image depicting 3UZ-FE engine (LS430) with 3rd mounting ear...simply acquire the bolt and from Lexus and installation is bolt in.
Power curve (Denso) for 130A alternator. (I believe this is power curve for same Denso alternator in 2001-2003 LS430) .the take away is better power production at lower RPMs where our engines tend to reside.over 1997 and earlier LS400's which have 2,700 RPM stall speed vs. 1998-2000 LS400 @2,200 torque converters and taller gearing ~3.73 vs ~3.26 for 1998-2000 LS400.
It is my belief the battery will not have to work as hard at lower RPM's and thus will last longer.
#12
Pole Position
Buy new P.S. pump from Lexus dealer.
Ditto for the Alternator, buy only Denso certified rebuilt...not aftermarket stuff...this you can obtain from dealer or Rock Auto...go 130A.
#13
Pit Crew
Thread Starter
I made it to the shop and dropped off car. White knuckles as I waited forever at stop lights waiting for the car to die, thankfully she made it in smooth LS fashion. I have requested the mechanics use only OE parts, would this be the same thing? I do not want aftermarket anything..... Requested a diagnostic prior to work just to be double sure. Headlight leveling warning came on while driving, hopefully related to current issue and not another one. 130 amp. Got it. Thanks all!
#14
Pole Position
I made it to the shop and dropped off car. White knuckles as I waited forever at stop lights waiting for the car to die, thankfully she made it in smooth LS fashion. I have requested the mechanics use only OE parts, would this be the same thing? I do not want aftermarket anything..... Requested a diagnostic prior to work just to be double sure. Headlight leveling warning came on while driving, hopefully related to current issue and not another one. 130 amp. Got it. Thanks all!
Also...ask to see old parts. The alternator may have core charge from dealer.
A new power steering pump does not have core charge with the dealer, so the shop should return it to you.
#15
Moderator
Ok I've read your post from a little over a year ago and studied all the pics. So far all I see is you asking other forum members IF this mod has been completed successfully. In a little over a years time no one, including yourself, has responded to the thread to say it has been completed successfully. I see a pic of a 1UZFE motor with a stock alternator and a pic of a 3UZFE motor with a stock alternator. Please excuse me if I seem pessimistic but I'd still like to see some evidence of this as a possibility. " simply acquire the bolt and from Lexus and installation is bolt in." isn't quite enough for me...