Help Needed - Electrical System
2001 LS430 Base, 115k miles, I live in Colorado. Car bought out of FL in March of this year.
Here's what happened: Last week I drove my normal 65 mile commute in the morning then parked the car, everything was normal. Went to restart the car 7 hours later and the accessory position worked fine but it didn't crank and then the electrical power went dead. Removed the key, popped the hood to look for anything obvious and, finding nothing, tried again to start. Accessory position power went on briefly then immediately died.
This weekend I removed the battery and took it to be tested at Advance Auto - tested fine. Battery is AAA brand with 7/17 stamp on it installed previous to my purchase in March with 108k miles. Terminals looked good but I cleaned them all anyway. I then charged the battery on my Battery Tender until fully charged (I don't know how long it took) then reinstalled the battery this morning and it started up just fine. I took the car back to Advance Auto and they checked the alternator and it looked good - 14v.
A couple items of note:
1) Last month the sunroof opened randomly on its own while driving on 2 separate days, both times after rain overnight. It hasn't happened since.
2) The alternator is dirty with rubber dust - I found a maintenance record from last year that suggests that the serpentine belt had ground down over the power steering pump. I believe the friction ruined the belt and sent dust over the alternator. This is the only maintenance record I have, all else is unknown.
I'm puzzled but maybe you all have a guess. If nothing works I supposed I will replace the alternator and battery but I don't like to throw parts at something.
Agree on charging system test. If you have a simple multimeter check voltage before starting it in the morning and immediately after starting it. Then do the same l when you get to work. If the voltage is dropping after ~60 miles then a true load test should isolate the issue. Plan to take jumper cables or a jump pack. What manufacturing date does the battery have? I doubt the plates were that sulfated but I don’t not know if your “battery tender” is new enough to have desulfication technology(for example like the PulseTech units)
Catalina45 - my charger is a simple "Battery Tender Plus" so I doubt it desulficates the battery. I'll do a search on that. Also I have attached a photo of the battery - I think it may have been manufactured 11/16 and installed 7/17 but it's not entirely clear to me. Regardless, shouldn't be too old.
atta
Catalina45 - my charger is a simple "Battery Tender Plus" so I doubt it desulficates the battery. I'll do a search on that. Also I have attached a photo of the battery - I think it may have been manufactured 11/16 and installed 7/17 but it's not entirely clear to me. Regardless, shouldn't be too old.
atta
https://www.impactbattery.com/blog/w...batteryminder/
Please report back on the results. You can pick up an inexpensive multimeter from Amazon which can be used for not just automotive but other tasks around the house. If you have a Northern Tool near you, they often give out their least expensive one for free. I have a high-dollar Fluke meter(which includes an amp test) that my brother (Toyota Master Tech) gave me years ago but use the free NorthernTool multimeter for basic household/shop tests as well. Northern doesn't even list it online.
Trending Topics
Celebrating Lexus & Toyota from Around the Globe
By the way, AAA batteries are typically via East-Penn out of their Dallas, TX Deka distribution and labeling center. For classic cars I love going to the center to get a "label free" battery and then using a "Battery Topper". The AAA truck driver has always been patient when in two of six trips over he ended up behind me in line. Good thing they are gear heads at heart as their order could be 20 or 200 batteries. Most likely you have their most popular "silver" series maintenance free battery. I have a few of these in classic cars and they have been excellent performers. They will spin over a heat-soaked 455 (462/468 CI Classic Pontiac with 10:50:1 compression) with no problem.
Looking forward to an update.
I took the car in to the shop today and it checked out clear - alternator, battery, everything. I have a multimeter and a jump pack so I'm going to keep driving it and checking up on it periodically.
I picked up a cigarette lighter voltmeter from HF (https://www.harborfreight.com/12-vol...ter-66842.html) and used it yesterday afternoon on a trip to the store in 95 degree heat after I drove my 65 mile commute. It read 'normal' (13.4 - 14.75) for the alternator while in park but read 'low' (<13.2) in neutral, drive and reverse. It read low the entire time I was driving and the entire time I was using the AC and radio.
I used it again this morning on my normal 65 mile commute in 60 degrees and it read 'normal' the entire time, again using AC and radio. It's supposed to be hot here again today so I will see what it reads this afternoon and I will use my multimeter in the engine compartment for more accurate results.
Perhaps it read 'low' yesterday afternoon because of the heat, perhaps it was because the battery had charged on my commute and the electrical system draw was low or perhaps it was because I'm using a cheap tool from HF. I haven't read of alternators behaving differently in high ambient heat though. It does have one ambient temperature-related quirk though: this winter in the morning when it was around freezing or below there would be an intermittent airbag warning light on the dash. It never came up in the afternoons or on mornings when it was above 35 degrees and I haven't seen it in for a couple months since it has warmed up around here.
I may update this afternoon if my multimeter uncovers anything odd in the heat but I'm starting to think that this may be something of a phantom issue and I don't want to spam the forum with my musings on the (hopefully) one-time issue.
Basically since the voltage that you should be reading includes the battery itself, that means your battery is also at that voltage. Now if your battery was half ‘dead’ like if you just got jump-started, it’s going to read low until you drive long enough for the battery to ‘catch up’ and ‘match’ what the alternator is trying to charge it to. So if you have a bad battery that is rejecting a charge due to a few cells/plates being bad, even with a good alternator, you can be reading a low voltage that doesn’t really go up. Think of voltage like fluid or air pressure. Your alternator may be blasting out the voltage (pressure), but if your battery is resisting the pressure from building, the pressure of the entire system will be lower and match the battery.
It’s important to note that I don’t know exactly what the LS430 should be charging at normally, but in a lot of/most cars, somewhere between 14.2v and 14.7v.
I have a little device called a Scangauge II that plugs into the OBD II port and reads a whole bunch of parameters from the ECU - voltage being one of them. Ever since I bought the car 3 years ago, it’s usually been as low as 13.3v up to 13.7v or 13.8v. Occasionally I’ll see it go up to 14.0v or 14.2v, but only for a brief moment. Revving the engine doesn’t change the voltage output for me. I was a little concerned at first, but the car never had any problems starting even when it went down to temps in the teens this and last winter.
The battery finally died one day after being in the car for about 5 years when my girlfriend was driving it a few months back and I was out of town. She got jumped and drove to an auto parts store and with my credit card, bought their most expensive or maybe one tier down for about $130 if I remember correctly. The car had been doing fine until last week when I parked in a parking lot for about an hour and a half with the stereo on at a reasonably high volume, and the headlights turned on for about 30 minutes as I was replacing and testing a couple of exterior and interior lights. All of a sudden my stereo starts skipping and turns off. Immediately I go to start the car hoping it wasn’t too late, but it was
. Now I’m the one getting jumped by a nice dude in this parking lot with a brand new lithium jump box. It fired right up, I drove 10 minutes home, then I let the car idle for 30 minutes at home. Didn’t run the car at all the next day, so I was pleasantly surprised that it started right up 2 days after it died. Haven’t had any problems since.Moral of that story, even a charging system that’s only running around 13.5v all the time charged a dead (10.2v when it died) within about 40 minutes enough for it to keep running.
Last edited by Mbodall; Jun 27, 2018 at 03:30 PM.




