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The stock 98-00 Denso OEM alternator is rated 100A. The alternator is Denso OEM with 37K miles. With all accessories running it is not up to the task at lower RPMs. The stock 01-06 LS430 alternator is rated 130A. Lexus increased amperage for a reason...
Does anyone know (what I mean by that is have you actually done this) if the LS430 alternator is plug-and-play..same size alternator housing..without; resizing to a different serpentine belt or modifying the stock wiring harness contacts/connector . Thank you.
The stock 98-00 Denso OEM alternator is rated 100A. The alternator is Denso OEM with 37K miles. With all accessories running it is not up to the task at lower RPMs. The stock 01-06 LS430 alternator is rated 130A. Lexus increased amperage for a reason....
The alternator in my 2000 LS400 had plenty of output, including at low RPM's, during the 10+ years I owned it. Yes, the output of the LS430 was probably increased for a reason - it had more optional electrically operated functions than the 98-00 LS400 such as separate air conditioning for the rear seat passengers, power reclining rear seats with power adjusting head rests and massage, and a refrigerated rear seat compartment for holding beverages.
OK, so on topic asking whether anyone has transplanted an LS430 alternator into an LS400...
As I reside in a cold climate, with the engine running, the stock 100A alternator is ill-equipped to power (in full or standby mode), ECU, Body ECU, Door ECU's, seat ECU's, Anti-lock braking, theft control ECU, Climate control ECU, Blower motor, Air conditioning manetic clutch (front defrost mode), Ignition system/coils, Instrument cluster, transmission ECU, Fuel pump and its ECU, Fuel pump resistor, fuel injectors, CD changer, Stereo head unit, amplifier, throttle motor, front running lights, front fog lights, HID low/ High beams, air suspension system, traction control pump/ECU, heated seats, windshield wipers, rear windshield defogger heating element, and sure I am missing a few more.. The aggregate ratings for fuses used for each of these respective circuits exceeds 100A.
Moreover, I am not just saying this just because I think its a good idea...Lexus increased alternator amperage to 130A.....quite possibly because 100A was inadequate. Toyota is a very conservative company, so it is highly unlikely any decision was made without considerable internal debate coupled with external input from their Lexus sales and service departments.
Perhaps someone has an alternator turn on RPM and power curve, but typically alternators seldom produce full power at idle and lower RPMs.
I can watch my tach and tell you that at about 1,100-1,200 the alternator is more fully able to perform in winter mode (and tried this using by installing spare OEM 100A alternator as a control), otherwise the battery has to pick up the slack with resulting life expectancy issues. The battery is designed for starting not in constant discharge mode.
As to whether the LS430 alternator is compatible with the LS400 wiring harness....attached is 2001 LS430 plastic connector shell replacement listing P.N. 90980-11349 for the Generator. (G2). (image of new multi-pin connector shell attached) I believe G1, P.N. 90980-09363 is the connector end for the main positive. The attached LS400 connector sheet lists the Generator multi-pin connector as 90980-11349 (G2)(SAME)and the main positive as 90980-09210.(G1) All are currently available from Lexus....
As an aside...anyone with a damaged wiring harness side (not component side) connector...As I understand it...90980- is the prefix for Lexus/Toyota connectors. The designating 5 digit P.N. suffix is usually stamped on the shell. Simply clean it thoroughly and use your camera to capture an image and then expand on your screen to read.
Meanwhile, looking forward to information responsive to the original inquiry.. Thank you!
As I reside in a cold climate, with the engine running, the stock 100A alternator is ill-equipped to power (in full or standby mode), ECU, Body ECU, Door ECU's, seat ECU's, Anti-lock braking, theft control ECU, Climate control ECU, Blower motor, Air conditioning manetic clutch (front defrost mode), Ignition system/coils, Instrument cluster, transmission ECU, Fuel pump and its ECU, Fuel pump resistor, fuel injectors, CD changer, Stereo head unit, amplifier, throttle motor, front running lights, front fog lights, HID low/ High beams, air suspension system, traction control pump/ECU, heated seats, windshield wipers, rear windshield defogger heating element, and sure I am missing a few more.. The aggregate ratings for fuses used for each of these respective circuits exceeds 100A.1 and G2
Now I understand. You live in the horribly cold climate of California. LOL!
I just checked the Toyota world-wide parts list and saw that the same 12V 100A alternator (part # 27060-50230) was used worldwide on the 98-00 LS400 ... U.S.A. including Alaska, Canada, Europe and on the Japanese market Celsior "C" with air suspension, rear seat air conditioning and power rear seat with massage.
Do you really think that Toyota engineers with the equivalent of doctorate degrees are stupid and that Toyota would risk putting an inadequate alternator on its "flagship" vehicle? I drove LS400 vehicles for over 24 years and the only alternator issue I ever had was when the one on my gen 1 LS400 was ruined by a leaking power steering pump. I never had a single problem with the engines starting, running and all accessories working down to about -15 degrees Fahrenheit.
If your alternator does not have adequate output, then it might be defective and need replacement. I've been active on this and other Lexus forums for up to 15 years and do not remember anyone wanting to put an LS430 alternator on an LS400.
There is nothing wrong with you trying to do it if you want to. I've done needless "improvements" to cars that might seem silly to others. If you are such an expert in these things, then you shouldn't have to be asking for help on this forum.
Try doing a search of this forum for topics relevant to your project. That should keep you occupied for awhile.
Or you could just buy a Mechmann HO Alternator like many of us have....
I have the Mechmann 320A alternator on my car to run my air system and stereo in conjunction with every acc in the dead of winter up here in Canada, where it is probably more required than California! Lol
The aggregate ratings for fuses used for each of these respective circuits exceeds 100A.
That is not how electronics work. A fuse is set at the maximum safe amperage then system can draw, not at its average opperating consumption.... Much like how your engine doesn't produce it's rated power numbers at all loads and RPM.
So what the aggregate amperage total is, is only important if all of those circuits were to overload at the same time.
In fact there is virtually no situation you can come up with where you will be drawing more than the alternator can produce on a stock car. And in those rare situations where it does, that is the exact purpose of the battery to pick up the slack.
If you have an aftermarket air system running 2x 40A compressors and a 2000W+ stereo, you are definitely going to need a bigger alternator, but it will also need to be bigger than the LS430 alt.
Automobile engineering is a process of evolution. Arguably, Lexus has upgraded its products over time and I am availing myself of certain factory upgrades where I deem practical or necessary.
I tell you this...Toyota's Doctorate engineers have made their share of design missteps..and this is before the airbag and sticking gas pedal imbroglio.
The blanket of scoff has no place in this forum.
Going forward, the only input I am seeking is on point with whether anyone has successfully transplanted the 130A LS430 Denso alternator in place of the 100A LS400 Denso alternator and how they proceeded. I choose to avoid Mechman for reasons I will not disclose here. Thanks.
Your evolution analogy is flawed in the sense that the entire car evolves with changing techology, not part by as problems arise. As Kansas pointed out, there is substantially more technology and electrical load on the 430s thus requiring a higher capacity alternator.
To answer your question, the search function may offer the answers you seek, also Google....
However, as Kansas also pointed out, it is unlikely anyone has ever done this or posted about a failed attempt in trying. It's a completely different motor and likely a completely different alternator case and mounting design.
If you feel so inclined, man up and give it a shot. A quick search on RockAuto will let you know if the part#s are the same or not.
As far as Mechmann goes, why not share?
The blanket of "for reasons I will not disclose" has no place in this forum....
Engineer SCMOO; WHAT don't you understand about not responding unless you have actually performed the specific swap described? Need I further digress to be more direct? Am well aware of Rock Auto and other resources. Thus far your responses here and elsewhere have been uninformed snipes. I will make my own way on this without your input
Or you could just buy a Mechmann HO Alternator like many of us have....
I have the Mechmann 320A alternator on my car to run my air system and stereo in conjunction with every acc in the dead of winter up here in Canada, where it is probably more required than California! Lol
This blog addresses issues for Mechman type alternators using smaller diameter alternator pulleys than OEM.
Good read, thanks for sharing. Not really sure why you needed to be confrontational and not post that before.
While I have noticed a major dip in amperage and voltage at idle with the AC, stereo going and the compressors kicking on, there really are no other options for HO alternators for my car at least.
My biggest issue with my Mechmann alternator is they pulley, while smaller than stock, is improperly sized and puts me right in between belt sizes. The stock belt is much to small, something Mechmann neglected to mention upon purchase, and the next size down (-3/8") is still loose enough that above 6000rpm I get belt slip/screech. The next size after that is 1" shorter than OEM and wont go over the pulleys. 1/2-3/4" shorter than OEM would be ideal for the as supplied pulley, or a larger tensioner or idler pulley supplied with the alternator allowing the OEM belt to be retained. I have CAD'ed up a smaller pulley and fastener (to replace the nut as a standard socket barely fits on the current pulley), i just need to find some time to get on the Lathe an Mill.
I am sure even the modest bump to 130amps would be beneficial to a lot of people, as it stands, i'm still stuck with Mechmann as my only option, as "half a solution" as it may be.
...Going forward, the only input I am seeking is on point with whether anyone has successfully transplanted the 130A LS430 Denso alternator in place of the 100A LS400 Denso alternator and how they proceeded...
Does this post help answer that?: https://www.clublexus.com/forums/ls-...ml#post9837469
"I've a 96 LS400. I am having some voltage drop issue with my car. I have recently changed the alternator, and the battery is also 6months old only..
I replaced the alternator with a donor 2002 celsior which is LS430.. since it owns a high amp alternator, i thought just to buy that one so it wont fail easily..."
EDIT - BTW, not much information there, but I would assume that his experience confirms fitment, and that if there are any voltage drop problems it is not related to incompatibility.
Does this post help answer that?: https://www.clublexus.com/forums/ls-...ml#post9837469
"I've a 96 LS400. I am having some voltage drop issue with my car. I have recently changed the alternator, and the battery is also 6months old only..
I replaced the alternator with a donor 2002 celsior which is LS430.. since it owns a high amp alternator, i thought just to buy that one so it wont fail easily..."
EDIT - BTW, not much information there, but I would assume that his experience confirms fitment, and that if there are any voltage drop problems it is not related to incompatibility.
The 2001-2003 LS430, SC430 130 amp alternator employs a third mounting ear...be sure and acquire the special threaded head bolt and nut that holds it in place..
Attached are images with p.n.
Bolt #3
01-02-16, 05:02 PM
1998-2000 ls400 alternator upgrade
