1998-2000 ls400 alternator upgrade
02-26-19, 09:01 AM
#31
Driver School Candidate
130 amp Sequoia alternator in 1994 Ls400
Swapped a 130 amp Sequoia alternator in a 1994 Ls400 25,000 miles ago and it works great. Not running the 130 amp near maximum all the time should allow it to last a long time. Only modification was swapping the rear plug-in to a square plug. I also ran a #4 gauge wire with 2 fuse-able links from alternator output to battery positive.
03-09-19, 08:33 PM
#32
Lexus Champion
Thread Starter
Electrical Load of Common Vehicle Accessories
Some power consumption figures to contemplate when replacing your alternator;
Amp Draws;
Air Conditioner 20-21
Air Suspension (?)
Audio Power Amplifiers10-70
Back-Up Lamps 3-4
Cigarette Lighter10-12
CD/Tuner with Amp 7-14
CD/Player/Tuner without Amp 2.5-5
Clock 0.3
Dome Light1-2
Electric Cooling Fans 6-15
Head Lamp Dimmer 2
Head Lamp (Low Beam) 8-10
Head Lamp (High Beam)13-15
Heater Defroster 6-15
Horn10-20
Ignition1.5-4
Ignition (Racing) 8-36
Instrument Panel 0.7-1.5
Lamp, Gauges1.5-3.5
Lamps, License Plate 1.5-2
Lamps, Parking 1.5-2
Lamps, Side Marker 1.3-3
Lamps, Tail 5-7
Power Window Defroster 30
Power Seats 25-50
Power Windows 20-30
Power Antenna 6-10
Pumps, Electric Fuel 3-8
Starter Solenoid 10-12
These are general ratings...if anyone has more specific ratings, feel free to share.
Amp Draws;
Air Conditioner 20-21
Air Suspension (?)
Audio Power Amplifiers10-70
Back-Up Lamps 3-4
Cigarette Lighter10-12
CD/Tuner with Amp 7-14
CD/Player/Tuner without Amp 2.5-5
Clock 0.3
Dome Light1-2
Electric Cooling Fans 6-15
Head Lamp Dimmer 2
Head Lamp (Low Beam) 8-10
Head Lamp (High Beam)13-15
Heater Defroster 6-15
Horn10-20
Ignition1.5-4
Ignition (Racing) 8-36
Instrument Panel 0.7-1.5
Lamp, Gauges1.5-3.5
Lamps, License Plate 1.5-2
Lamps, Parking 1.5-2
Lamps, Side Marker 1.3-3
Lamps, Tail 5-7
Power Window Defroster 30
Power Seats 25-50
Power Windows 20-30
Power Antenna 6-10
Pumps, Electric Fuel 3-8
Starter Solenoid 10-12
These are general ratings...if anyone has more specific ratings, feel free to share.
03-10-19, 09:33 AM
#33
Driver School Candidate
Running at night could easily cause a 90 to 100 amp draw on the alternator. I upgrade to a alternator with more amp output if available on any vehicle I own. An example of this is the 89- 94 Maxima's I own came stock with 70 or 80 amp alternators. The alternator barely makes it to 100,000 miles. The Mercury villager uses the same VG30 motor and came with a 125 amp alternator. Since putting on the 125 amp alternator no more alternator failures.
04-07-19, 11:16 AM
#35
Also, as total load increases, voltage will dip, which will reduce total current draw. So there is an additional self-regulating factor in here.
Another thing to consider when looking at things on a component-level basis, is that the Alternator has a fusible link = 120A on my '91; sure what it is on others. But that number suggests a limit of what the Lexus designers considered would be a maximum expected total load - and probably the entire electrical system downstream from that is designed accordingly.
A higher rated alternator is definitely likely to perform better, so if this is plug and play, it seems like a great upgrade. I think I remember an older post from Yoda showing an increased alternator output capacity at lower RPM, which would be especially helpful.
Without studying things too much, I would not change the 120A fusible link when upgrading the alternator, since there is no guarantee the rest of the electrical system would be sufficiently protected with a higher rated link. If blowing the 120A link were a real concern, adding a breaker upstream of the link might protect against needing to replace those while finding out. You'd never be able to get the higher max capacity of 140A or whatever it is, due to the fusible link remaining in place. But you'd still benefit from better capacity vs. RPM below 120A.
04-07-19, 03:50 PM
#36
Lexus Champion
Thread Starter
One important thing not on that list is the charging load of a discharged battery, which I'm guessing could be pretty high.
Also, as total load increases, voltage will dip, which will reduce total current draw. So there is an additional self-regulating factor in here.
Another thing to consider when looking at things on a component-level basis, is that the Alternator has a fusible link = 120A on my '91; sure what it is on others. But that number suggests a limit of what the Lexus designers considered would be a maximum expected total load - and probably the entire electrical system downstream from that is designed accordingly.
A higher rated alternator is definitely likely to perform better, so if this is plug and play, it seems like a great upgrade. I think I remember an older post from Yoda showing an increased alternator output capacity at lower RPM, which would be especially helpful.
Without studying things too much, I would not change the 120A fusible link when upgrading the alternator, since there is no guarantee the rest of the electrical system would be sufficiently protected with a higher rated link. If blowing the 120A link were a real concern, adding a breaker upstream of the link might protect against needing to replace those while finding out. You'd never be able to get the higher max capacity of 140A or whatever it is, due to the fusible link remaining in place. But you'd still benefit from better capacity vs. RPM below 120A.
Also, as total load increases, voltage will dip, which will reduce total current draw. So there is an additional self-regulating factor in here.
Another thing to consider when looking at things on a component-level basis, is that the Alternator has a fusible link = 120A on my '91; sure what it is on others. But that number suggests a limit of what the Lexus designers considered would be a maximum expected total load - and probably the entire electrical system downstream from that is designed accordingly.
A higher rated alternator is definitely likely to perform better, so if this is plug and play, it seems like a great upgrade. I think I remember an older post from Yoda showing an increased alternator output capacity at lower RPM, which would be especially helpful.
Without studying things too much, I would not change the 120A fusible link when upgrading the alternator, since there is no guarantee the rest of the electrical system would be sufficiently protected with a higher rated link. If blowing the 120A link were a real concern, adding a breaker upstream of the link might protect against needing to replace those while finding out. You'd never be able to get the higher max capacity of 140A or whatever it is, due to the fusible link remaining in place. But you'd still benefit from better capacity vs. RPM below 120A.
https://www.clublexus.com/forums/ls-...do-i-have.html
0
LS430.alternator Y winding (visible) is more efficient.so 130 amps instead of 100
LS400 alternator . Old style round wire and winding configuration (visible), hence only 100 amps
LS400 altermator.
2001-2003 LS430 alternator....notice third mounting ear. bolts right in. Plug and play
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borgey (04-13-19)
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BNastee (05-07-24)
05-04-19, 06:24 PM
#39
Racer
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.
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 following users liked this post:
Sin1UZFE (04-28-20)
04-23-20, 11:26 AM
#41
Lexus Champion
Thread Starter
Possible explanation why toyota used third mounting ear on ls43o alternator
The 100A alternator employs a single Aluminum casting to encase lamination, while the 130A hairpin style uses the front and rear Aluminum housing section to clamp onto the steel laminations, so only the 4 long spindly alternator bolts are clamping laminations between front and rear Aluminum castings.
Apparently the third mounting ear and mounting bolt are employed to help stabilize the front housing section.
100A old style alternator on top. 130A hairpin on bottom...disassembled for polishing and instsllation of Litens OAD.
Top view depicting 3rd mounting ear.
Last edited by YODAONE; 04-23-20 at 11:39 AM.
04-28-20, 01:15 PM
#42
Intermediate
So my 98 seems to have a dying alternator. I am looking at this Mechman Alternator like this thread suggested. My alternator is only putting out 11V and dropping to like 9.5V. When the car starts the reading will jump to 14.3 but no matter how much driving I do the alternator will never charge up. Its possible my alternator or some wires are corroded and a bad ground or connection somewhere is my issue.
04-28-20, 01:23 PM
#43
Racer
So my 98 seems to have a dying alternator. I am looking at this Mechman Alternator like this thread suggested. My alternator is only putting out 11V and dropping to like 9.5V. When the car starts the reading will jump to 14.3 but no matter how much driving I do the alternator will never charge up. Its possible my alternator or some wires are corroded and a bad ground or connection somewhere is my issue.
04-28-20, 02:07 PM
#44
Moderator
So my 98 seems to have a dying alternator. I am looking at this Mechman Alternator like this thread suggested. My alternator is only putting out 11V and dropping to like 9.5V. When the car starts the reading will jump to 14.3 but no matter how much driving I do the alternator will never charge up. Its possible my alternator or some wires are corroded and a bad ground or connection somewhere is my issue.
Why do you need a 240 amp alternator?
04-28-20, 02:10 PM
#45
Racer
Oops......
Last edited by Sin1UZFE; 04-28-20 at 02:13 PM.