ShawnD

Hey guys!
My 2008 GS350 has 92K miles on it and has been trouble free...until about 3 weeks ago.

I drove the car to work and it acted fine. Came out and it was dead; got a jump took the battery to be tested at Autozone and it tested bad. Picked up a replacement and this is where are all the issues begin. Go to leave the next morning and car is dead. Have the factory alternator tested; it reads bad. Changed out the alternator (remanuf from Oreilly's). Fast forward to this past weekend. Got the car up and running and it was reading 14ish volts while the car was running (new alternator replacement battery #1 RP1; RP1 was dead/recharged 3 times) 13ish under load. Then the "check charging system" text and battery warning icon came on. Drove the car for an hour to charge up RP1 and the warnings never reset/turned off. Take to autozone have them double check battery and alternator output on their machine vs my digital volt meter. Numbers reading good. Take the car home; still concerned about the light but it's at least running now. Check it 2 hours later and the car is dead. Take RP1 back to Autozone and they attempt to charge it (have to in order to give me a replacement) and it won't charge. They give me RP2 and it's reading fine buuuuut,both warning text/icon's are still lit up like a christmas tree.

Get up to go the gym this morning and it's dead as a ****ing door nail. I am at my wits end with this thing. Any and ALL suggestions are welcome! New alternator; TWO brand new batteries. Could it be the alternator since it was a remanuf one? I double checked all the bolts/nuts/plugs and all the fuses in the car (that was time consuming!) and everything checks out fine on that front.

TIA!
Shawn

ez12a

I've read something about parts store reman alternators dont use the same regulator components that Toyota uses, causing issues. But this is just stuff i've read and nothing more.

It sounds like a power draw issue while the car is off though.

Lukas99GS

Do you drive with your headlights on? I know my driver door switch a lot of times doesn't work when I open the door so there's been times I've left my car and the headlights were on the whole time only to come back to a dead car

ShawnD

I always lock the car and then out of habit hit the button on the remote effectively turning the lights off. I have the headlights set to Auto; I checked all of the lights, interior and exterior including trunk through the pass through, and there is nothing on when the car is parked.

I guess I could pull the alternator (getting REALLY good at this! 12 min and it's out.) and exchange it. The issue is do I go full Lexus or try another remanuf but from a different parts store? Not sure if they all come from the same generic remanuf pool or not.

tekkie

Not sure if this can help, but when my alternator went bad it was due to a diode on the alternator that was semi-shorted. It was draining my battery when the car was parked overnight. I thought it was the battery so I replaced it and the battery went dead again the next day. It was not until I saw some smoke coming from underneath the car that lead to the diagnose that my alternator was on its way out. I replaced with a remanuf one and had been working fine for over six months now.

gr8fulRed

I replaced my alternator on my 09 GS weekend before last. I used a remanufactured from Napa. It was identical to the OEM I pulled out. I had called my near by Lexus parts dept and got a quote of $494 for a remanufactured. I asked about new and he said, "we normally don't sell those..because they are $1004. I paid $128 at Napa and it's working like a charm. No issues. The job itself was a massive pain in the ***, but the Napa unit is working properly. Lexus was going to charge about $1000 to put in a remanufactured. Check that, I spent $215 on the Napa alternator.

nobelnabil

I am no expert on this, but If I were you , then I would get a DC amp clamp meter, check the current draw on the alternator while the car is running and the current draw on rest (on the battery) and get an idea if there is a short that is draining your battery or exhausting your alternator.

ShawnD

UPDATE: I got a replacement alternator (remanuf from O'Reilly's as it was originally purchased there) and put it on. Jump start it (battery is dead) and the battery is reading 13.4-13.9 while the car was on; "Check Charging System" text and battery icon are still on at the cluster. Turn the car off; put the volt meter on the battery and it drained back to zero in under two minutes; so that at least tells me that the alternator to battery connection is where I need to pinpoint.

I am going to re-check the #23 fuse for the ALT on the passenger side/engine compartment fuse block tonight when I get home.

Any ideas on something simple that I am overlooking?

ibidu1

iTrader: (1)

Sounds to me like you have a pasasitic draw to me here is a video that may help you.

RXGS

iTrader: (2)

I wish the alternator was as easy on the RWD as it was on the AWD. Just had mine done and cost almost $800 at an independent, which was better than the $1200 the dealer quoted, but still.

XxGoKoUxX

ibidu is right, you seem to have some form of parasitic draw. Fuses will not be a culprit of what is draining the battery, from my personal experience.

I would jump start the car. drive it around, and then instantly disconnect the battery terminals.

See if the battery is holding charge (at all) and from there I would then charge the battery manually.

I would start off by disconnecting fuses one by one to see which item in your car is parasitically draining your battery.

EDIT: I just glanced over the youtube video. It explains everything out step by step (using a multimeter to find current draw and removing fuses one by one).

GL!

ShawnD

Update: I put the battery on a charger overnight (Tues night) and gave it a nice, full charge. With a full battery I started down the road of checking for a parasitic draw using this video:
The car was pulling 1.XX DC Amps or .1XX MiliAmps using this method, definitely well below what would be considered a major draw down (according to this video at least). I started with the under hood fuses and there was no drop on the volt meter. *re-watched the video to make sure I had it all setup correctly* Then I reconnected the battery to the car; fired right up, but the damn "Check Charging System" and battery icon are STILL shining bright. I pulled that fuse and could tell that the car didn't like it, although the warning lights did turn off. Battery dropped down to 12.3X with it running; so I replaced that fuse and it started charging back up and putting juice back into the battery.

I let it sit fully connected overnight, came out this morning to a full 13.XX battery. Fired right up, drove it to the gym. In gym about an hour, came back out and she fired right back up. I live about 1/4 mile from the train station so I have been training into the office (did again today) just to be safe. This is all well and good except that I start a new job on 2/5 and my car will now be my office so I have GOT to get this damn thing sorted out.

XxGoKoUxX

I'm confused. 1.00A is 1000mA.

You should be seeing a 0.5A or 500mA draw from the car (MAXIMUM) if you follow that video.

On another note. You should get your car checked for that "Check Charging system" notification. Something else might be wrong with the system.

I would swing by a local autozone/advanced auto to have my car load tested to see if the charging system is working properly. In one scenario, your car can charge, but the charging system (electronic portion of your alternator) could still be faulty, or not compatible with your car, causing the message to go off.

GL! Keep us updated!!

tcr101

iTrader: (2)

Might be worth it to clean your battery contacts.. I had problems previously on another car, but never had the "check charging system".

Get a mixture of water/baking soda and see if your leads contacts "phizz". If it does, the corrosion could be the reason why there's a voltage drop and your battery isn't charging.

2013FSport

iTrader: (2)

A post up there talked of bad diodes in an alternator says a lot but if they tested this properly, they should have caught it. Alternators make Alternating Current (AC). 6 pairs of diodes convert the AC output to DC (Direct Current). When these high current diodes leak, they draw a lot of current. Likely AMPS and will slaughter a battery. That said one bad diode of 6 and the alternator still charges!!! BUT - It Murders your Battery when not running.

This seems likely. However, getting two duds in a row, seems very unlikely.

A simple test for those who do not have an Expensive DVM that measures AMPS, is this. Buy a 12V 55W H3 halogen lamp and a couple sets of test leads. I suggest those with Banana clips that you can connect various sizes of Alligator clips to at both ends. Connect one test lead to the case of the halogen bulb. Connect one test lead to the free wire from the bulb. Clamp the free wire end to the Negative battery cable.
With the Engine and Key off, all doors closed, all lights off, CAREFULLY disconnect the Negative Side of the battery while using your alligator clip assembly to KEEP THE BATTERY CABLE CONNECTED TO THE BATTERY. Do not break the connection between the battery and the Negative cable. I know this sounds impossible but there is a trick. Simply stick a screw driver on the battery post and connect your test lead to the shank of the screwdriver by the handle. Now as you slide the loose negative terminal up you have a connection.

If that light burns your eyes from shining so bright it hurts, you have a draw of 4 Amps or so that will kill your battery (55W / 12.7V = 4.3Amps). If it barely lights, this is a good sign but what it means is you need a smaller bulb! A common 12v test lamp will do. Something that only draws a little current.
My Snap-on test lamp is good for 44mA. Simply connect the clamp to the battery cable and touch the test lamps point to the battery post. Now lift the battery cable up and don't touch the shank. Again, if the Light lights, it's drawing current. A dim light is best. This is a simple test to gather facts, DO YOU NEED MORE TESTING down to the mA level?

In the ideal situation, current does not flow and the lamp does not light. I have not measured my 2IS with Nav to see what it draws when all is off.
This is a bad example but my 2008 Yamaha street bike draws 0.00013 Amps when off. It's 10 Amp battery will last for 4 months when not ridden. If I had to to guess the IS/GS series should draw something less than 15mA (0.015A). Even this will kill a battery in no time.





Notice Small test lamp draws less 44mA. Again, a bright light is BAD. You want NO Light at all. This is a small incandescent lamp and 0.044A is a lot in terms of leaving a car off for weeks. Do note that the 2IS shuts down hardware at 15 days, 30 and 45 to reduce parasitic losses. No clue about the GS series.


TAG - JJD952 2IS Electrical