Alternator replacement 2005 LS 430
I had something similar happen to my previous sealed AAA battery. Left the map light on at long term parking for a week. Needless to say it was dead when I got back 8 days later. The LS has a safety cut off feature that will stop draining the battery at a certain voltage to prevent ruining the battery. I did not even charge it with a charger. Just jumped it and drove home. Probably not the best way but I needed to get home. Amazingly the battery was fine.
When I replaced my alternator I wanted a new battery even though my old one did not test bad. After 5-6 years that is enough for me.
When I replaced my alternator I wanted a new battery even though my old one did not test bad. After 5-6 years that is enough for me.
New Denso is on deck!
Well i guess it's my turn up to bat on replacing the alternator. Batt light came on about 2 months ago accompanied by a noise and burning smell. Was still able to drive home with no issues. Came back out a while later to no noise, no smell, and light not on. Ok so this bought me some time since the issues didn't return until although i did get an light, high pitched roaring sound upon cold starts. Fast forward to last night, started the car with a small noise and batt light back on. Drove about 20mins to downtown DC and boom, all hell broke loose. Most of the indication lights popped on, dash lights were dim also. Car stalled. Luckily i was able to park the car in a space so i could wait for a tow. Strangely after sitting for maybe 20mins or so, the car would start again fine but although batt light would be still on. Idles good for about 5mins till hell returns. Towed home safely and now im sourcing a new unit online as we speak. Ebay, Rock Auto, and Amazon are the front runners. Installation will be handled by yours truly but any tips or advice anyone has would be greatly welcomed.
It's definitely an cheaper option that I will explore.
Pole Position
Joined: Mar 2008
Posts: 2,146
Likes: 70
From: Illinois
Well i guess it's my turn up to bat on replacing the alternator. Batt light came on about 2 months ago accompanied by a noise and burning smell. Was still able to drive home with no issues. Came back out a while later to no noise, no smell, and light not on. Ok so this bought me some time since the issues didn't return until although i did get an light, high pitched roaring sound upon cold starts. Fast forward to last night, started the car with a small noise and batt light back on. Drove about 20mins to downtown DC and boom, all hell broke loose. Most of the indication lights popped on, dash lights were dim also. Car stalled. Luckily i was able to park the car in a space so i could wait for a tow. Strangely after sitting for maybe 20mins or so, the car would start again fine but although batt light would be still on. Idles good for about 5mins till hell returns. Towed home safely and now im sourcing a new unit online as we speak. Ebay, Rock Auto, and Amazon are the front runners. Installation will be handled by yours truly but any tips or advice anyone has would be greatly welcomed.
Driver
Joined: May 2014
Posts: 108
Likes: 2
From: Poland
I have checked voltage output on my LS and I was a little bit confused when I saw about 14V.
I have read in service manual, that measurment should be performed at 2k rpm with two scenarios - first one with amperage around 10 A, and the second one with amperage 30A or more (high beam and blower at high). Standard voltage 13,2-14,8.
Output level is controlled by ECU and depends on temperature. So I think the best way to get similar conditions is to measure with heated engine.
Denso alternators have terminal S (more info here: http://wilbo666.pbworks.com/w/page/3...latorSTerminal) which is connected to battery (by fuse 5A on Fuse block near battery) and works as an feedback.
I have replaced terminal S fuse by an schottky diode. This solution increased alternator voltage output about 0,25, so now I have output level about 14,25V. To increase output by an 0,5V it should be used two serial connected schottky diodes.
I have read in service manual, that measurment should be performed at 2k rpm with two scenarios - first one with amperage around 10 A, and the second one with amperage 30A or more (high beam and blower at high). Standard voltage 13,2-14,8.
Output level is controlled by ECU and depends on temperature. So I think the best way to get similar conditions is to measure with heated engine.
Denso alternators have terminal S (more info here: http://wilbo666.pbworks.com/w/page/3...latorSTerminal) which is connected to battery (by fuse 5A on Fuse block near battery) and works as an feedback.
I have replaced terminal S fuse by an schottky diode. This solution increased alternator voltage output about 0,25, so now I have output level about 14,25V. To increase output by an 0,5V it should be used two serial connected schottky diodes.
Consider buying reman. Denso if you have the time. Local rebuild shop may/may not use Denso replacement component parts. Choice may also depend on how long you plan to keep your LS, and peace of mind (when these quit, you've experienced what can happen). See https://www.clublexus.com/forums/ls-...001-ls430.html
Pole Position
Joined: Mar 2008
Posts: 2,146
Likes: 70
From: Illinois
You'll be happy knowing you have the OEM-equivalent. I removed mine too in advance of the replacement alternator being available for next-day pick-up. It's a very straight-forward DIY. Your battery will appreciate the new alternator as well. Easy starts this winter in dc.
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Lead Lap
Joined: May 2006
Posts: 3,680
Likes: 302
I've read a bunch of posts of replaced alternators for the LS430. Unless the alternator is just not putting out (under 13volts) the battery or something else can be the culprit. I read about a member replacing his alternator because he was not happy with seeing 13.6 at times. HIs new alternator put out the same amount once it was warmed up with everything on. I just got a new battery after 3 1/2 years with the older one I replaced at that time.. My alternator puts out anywhere from 14.2 when cold to 13.5 when warm with everything on. . If it not broken, don't fix it. I'm not replacing my alternator. Over 3 years here in Florida without a dead battery is good enough for me. Our alternators are not made to be putting out a constant 14+ volts.
Last edited by Bocatrip; Oct 15, 2015 at 11:07 AM.
I've read a bunch of posts of replaced alternators for the LS430. Unless the alternator is just not putting out (under 13volts) the battery or something else can be the culprit. I read about a member replacing his alternator because he was not happy with seeing 13.6 at times. HIs new alternator put out the same amount once it was warmed up with everything on. I just got a new battery after 3 1/2 years with the older one I replaced at that time.. My alternator puts out anywhere from 14.2 when cold to 13.5 when warm with everything on. . If it not broken, don't fix it. I'm not replacing my alternator. Over 3 years here in Florida without a dead battery is good enough for me. Out alternators are not made to be putting out a costant 14+ volts are a contstant basis.
Pole Position
Joined: Mar 2008
Posts: 2,146
Likes: 70
From: Illinois
I've read a bunch of posts of replaced alternators for the LS430. Unless the alternator is just not putting out (under 13volts) the battery or something else can be the culprit. I read about a member replacing his alternator because he was not happy with seeing 13.6 at times. HIs new alternator put out the same amount once it was warmed up with everything on. I just got a new battery after 3 1/2 years with the older one I replaced at that time.. My alternator puts out anywhere from 14.2 when cold to 13.5 when warm with everything on. . If it not broken, don't fix it. I'm not replacing my alternator. Over 3 years here in Florida without a dead battery is good enough for me. Out alternators are not made to be putting out a costant 14+ volts are a contstant basis.
If I didn't replace my alternator, my '01 LS would still be dead in my garage. I wish I had replaced it before it quit on a Chicago expressway in late December at midnight. See https://www.clublexus.com/forums/ls-...001-ls430.html As soon as I replaced the alternator, the car started and has been fine ever since. The voltage regulator is also inside the alternator. Why anyone would wait until the alternator dies is akin to waiting until the brakes don't stop the car to change them. I'm not advocating to change it without having the output tested. It's an easy and inexpensive DIY. Heat takes a severe toll on alternators and batteries, so mileage is not the only reason to change the alternator.
Last edited by Tom57; Oct 14, 2015 at 10:39 PM.
Well all is well! Received my Denso part and Bando belt today and was back on the road in less than 2 hours. Really not a bad job. Even when my old hydraulic floor jack could only lift the car up maybe 8 inches, i was still able to get things done. Only issue i had was not with the installation. The parts i ordered thru Amazon shipped separatly. The altenator arrived as soon as started to break everything down but no belt so i had to put the old one back on. No sooner than me finishing up with tools packed away and the car idling, here comes the UPS man. Needless to say i when ahead and installed it right then and there, getting burned by hot hoses and all. 
Nevertheless, car is back purring again. I thought i was suppose to get 14v when i check the menu(option+clicks) but only read 13.5-13.8. Is that ok?? Anyways, the car seems more serene or quieter than before. Not sure if was from disconnecting the batt for more than hour or if it really has something to do with the new part. Happy nonetheless! 
Nevertheless, car is back purring again. I thought i was suppose to get 14v when i check the menu(option+clicks) but only read 13.5-13.8. Is that ok?? Anyways, the car seems more serene or quieter than before. Not sure if was from disconnecting the batt for more than hour or if it really has something to do with the new part. Happy nonetheless!
Pole Position
Joined: Mar 2008
Posts: 2,146
Likes: 70
From: Illinois
The new alternator does make a difference in engine performance ... I noticed same when I changed mine. As for voltage output, it will fluctuate per the voltage regulator, battery condition/draw down, and how long the engine has been running (lower voltage output over time as battery is re-charged). Disconnecting the battery, of course, resets the ECU too. What year is your LS?
The new alternator does make a difference in engine performance ... I noticed same when I changed mine. As for voltage output, it will fluctuate per the voltage regulator, battery condition/draw down, and how long the engine has been running (lower voltage output over time as battery is re-charged). Disconnecting the battery, of course, resets the ECU too. What year is your LS?
. I'm just glad to be back on the road. Borrowing my GF's car is an hassle. 