Hi, I have a 1997 Lexus ES300 with approximately 100k miles and have been having a battery issue that I have not been able to solve. The problem is intermittently the battery will die and will have to be jumped off. I have replaced the battery 4 or 5 times over two years and recently replaced the alternator and the issue continues. The problem typically occurs when my wife is driving around town doing errands making multiple stops. And has happened several times when she has sat in car on phone talking while car idles in summer heat. Then goes in store and upon returning car will not start. Basically you hear the clicking because battery does not have enough charge requiring a jump. Very frustrating and dealer hasn't solved because they can't replicate the problem. Although they offered to tow it for free the next time it happens just to check it out before its jumped off. Any help would be appreciated.

 

Bring your car to Autozone. They'll perform a complete charging system and test your battery free of charge.

I think they'll also give you a printout of the results.


Phil

 

Wait. How did you know the battery was dead? Did you test the voltage or was this just a plain guess? Since you mentioned a click and no start, I'm leaning more towards a starter problem, than a battery/alternator issue.

 

A word of wisdom to all. The alternator in your car is designed to maintain a battery charge, not recharge a dead one. When you have to jump start a car with a dead battery you are killing your alternator. It has to then run all of the cars electrical systems and also try to charge a battery that can be pulling as much as 100 amps. When this happens two things take place. Sometimes the thermal circuit breaker built into the voltage regulator can be tripped but it is usually too late. By then the diodes are glowing and beginning to lose their integrity. Then they begin to leak and when that happens they will cause a drain on the battery when the car is shut off. Also the ripple or AC in the circuit will make the voltage regulator go nuts trying to hold a steady voltage. The same damage can occur when you jump start someone else's car with your engine running. Imagine using a 120 amp alternator to power a starter pulling as much as 700 amps. If I were you I would remove my alternator and have your local Napa or AutoZone bench test it. I'll bet you have bad diodes.

 

Thanks guys. Yeah, I've had both Autozone and Sears test multiple batteries I've had to replace and they have been in a state of discharge and sometimes they replaced them under warranty. The last time the car died, I would jump the car off and as soon as I removed the jumper cables the car would die in less than 1 minute. That is when Toyota said the alternator was not working and replaced it. They tested the battery and said it was still good and did not replace. Then about 2 weeks later the car would not start again. Maybe all the jumping off damaged the alternator. I'm not sure but am very tired of it. It's a great car except for this issue.

 

Did they fully recharge the battery when the alternator was replaced?

 

A similar issued happened/happening with our 2002 sc 430. The battery ran down from non use so I charged it up, drove it for a day then the car was dead the next day. There is no electrical power at all. I tried to recharge but nothing, then changed the battery and still dead. The battery charger is the lexus charger unit.

 

Check how much power your alternator is putting out when running. Then check for parasitic drain

 

Hello all,

I have had similar issues with my 1999 ES300 for the last 5 years. Although not the extremely frustrating issues your wife is having. I wake up to dead car not hands full of shopping bags dead car.

2 batteries and 3 alternators have been sacrificed.
Fortunately the alternators from Autozone are lifetime warranty so the Autozone tech does a test and I just change it there in the parking lot.

I am almost positive it is some sort of parasitic draw but have never tested it (today I am, thanks for the vid link).

When you first start the car interior lights and daytime running lights will kind of "pulse"; not strobe light speed but a slow 1, 2 dim, 1, 2 bright 1,2 dim, etc. I hope I explained that clearly.

Should I try to find a higher quality alternator instead of the autozone brand?

Regarding alternator power output: Has anyone used Torque smartphone app and Bluetooth dongles for voltage measurement?
How accurate is it?

 

Torque will only give you the voltage at the OBD2 port which is regulated by the ECU not the alternator. I had the flicker myself and found a leaking diode in my alternator. I also added a better ground wire to the block and the body... problem solved.

 

So if Torque is measuring at the port than what use is the voltage reading?
Is it the voltage coming from the battery or the voltage being put out by the alternator?
What powers the ECU while its running? I know the battery keeps the clock and settings saved like a CMOS battery in a PC but does the ECU only get power from the battery?

On my last alternator death I plugged in the ODB and was getting like 6 volts as I limped it to autozone.
When running the car now I get a range from 11.9v to 14v which from what I read is within spec.

Can you elaborate on adding a better ground wire? block as in engine block?

thanks

 

I was actually looking a the wiring in the engine bay and thought the leads running from the battery looked a little small.

As far as grounding is this what you were talking about?
http://www.andysautosport.com/lexus/...n/ground_kits/

I don't even know where I would start with one of these kits.

 

Wow, very informative video on parasitic drain but man, that guy was long-winded!

 

The ECU has a built in regulator but like anything it can only operate in a given range.

"On my last alternator death I plugged in the ODB and was getting like 6 volts as I limped it to autozone.
When running the car now I get a range from 11.9v to 14v which from what I read is within spec."

It should read somewhere between 13.6~14.4 when running. There must be a bad connection somewhere. Or there is something pulling massive amounts of power to drop it to 11.9 volts when running. I recall a TSB for the 98~04 Sienna with a similar charging system that stated that at idle with a lot of things running like defrost, rear window defrost, headlights and a lot more the charging system would not be able to keep up and would go into discharge E.G. running on the battery where you would see a steady decline in voltage. See if the voltage is where it should be when you bring the RPM to about 1100 RPM or so. Toyota wanted $350 for an upgraded alternator for my Sienna to fix the problem. What I did was put a smaller diameter pulley on my alternator to make it spin a little faster at idle and that fixed it. Not sure if this will fix your problem but try turning some things off and see where the voltage goes. I have not had this problem with my ES 300 but I would do the same if I did. As for the ground there is no need for a kit. What a ripoff! all you need to do is get a tape measure and measure from the NEG post of your battery to the torque strut mount on the engine and then from there to the body. Next go to Napa and get two 8 Gauge woven ground straps then simply attach. Should cost about $10. I'll post some pics when I get a chance.

I hope this helps you out.

 

I see about where I would attach it in the engine, but where on the battery? Do I just clamp it on a insulated part of the cable?

I did the parasitic draw test...
but if my readings are correct it was well below what the video said.

0.033 a

but when i first connected it would get up to
0.50 a

I am assuming its ECU energizing?