18 replies to this topic

[Montalvo]

In August of 2006, I posted a question on this forum about the battery going dead on my 2000 RX300, thinking I might be able to fix the problem on my own. But after replacing the battery and getting some helpful advice, I finally relented and took the car to my dealer. He replaced the body control module for $812.47 and that seemed to fix the problem.

Fast forward to this past weekend...another dead battery. The battery is, of course, only 16 months old (10K miles) and I didn't do anything that would have caused the battery to run down. I've since recharged the battery and attached a trickle-charger but it appears to be continuing to have to add juice to keep the battery charged (in other words, it appears that there's an on-going loss of current somewhere). Given my last experience, I can't help wondering whether this has to do with the previously replaced body control module and, if so, did they just correct a symptom by replacing it when something else was actually causing it to go bad and it's killed the new one now?

So...what to do now:

Take it back to the dealer?
Buy a body control module myself, replace it and see if that fixes the problem?
Run some tests to verify the amperage leakage?
Start looking at the 2008 models?

Thanks for any suggestions you can offer.

Bob

[carguy07]

I would say start over at step one, fully charge the battery and have it tested. Sounds a lot like your previous problem but until you verify that it is not the battery you are going in circles.

[Montalvo]

Thanks, carguy07. I kinda thought that would be the best answer but was hoping someone would say, "Oh, I went though the same thing. That year/model has a short in the XXXX...check that out first."

Off to check the battery and then we'll see where to go from there.

Bob

[carguy07]

Make sure you give it a full charge before you take it to be tested.

Let us know what you find.

I doubt you are the first one to have the problem.

[carguy07]

Stupid question, but is the battery totally dead? No lights, etc, or just not starting? Is it trying to start at all?

[lenore]

First, what kind of battery is it? I too live in the area, and can tell you from experience with many cars, that Kragens auto store batteries suck big time. I have had them fail over and over, in many cases less than 6 months. Switched to A Costco battery, problem fixed. It is very difficult to check a battery when a cell may be shorting intermitantly. That said, there is always a current drain on the car, due to locks, and the system that monitors the locking system. High current drain is abnormal. I am sorry I dont have a figure as to what that would be, but over 2 amps would be a lot with the vehicle off. You could have a problem with the Driver door ECU. It too is hot all of the time.

[Montalvo]

First, thanks to all who took the time to respond. I took carguy07's advice and started by having the battery checked. I had bought the battery at Wal-Mart and they charged it and then checked it for free (it was still under warranty). They said that although the battery checked out fine, the alternator was only putting out 13.73 amps and was either starting to go or had a problem. I took their word for it (probably not the best idea) and decided to buy an alternator.

I called Napa Auto Parts and they had a new (or maybe rebuilt...I didn't ask) alternator for $217 but it was at a store twelve miles away. Having not yet read Lenore's message about lousy Kragen batteries, I then called Kragen and they had an alternator in stock...and it was only $137 (rebuilt) so I bought it. It was an Autolite Pro-Tech with a lifetime warranty and 24 months of free roadside assistance. Hope it doesn't have the same quality as their batteries!

I'm in the process of installing it and will report back to let you know if it fixed the problem.

Bob

P.S. I read another post about the battery drain associated with having a car sit for long periods. In my case, we took two week-long vacations in December and the battery died shortly after returning from the second one. I'm thinking that the battery was so low when we returned that the weak alternator wasn't capable of generating enough juice to re-charge it. The car's got 91K miles on it so I guess having things like alternators crap out on you is par for the course.

[lenore]

13.73volts is not a bad alternator. And I hope your alternator is good, I have had very bad luck with the alternators from Kragen also. My son's Ford ranger went through 3, and they were the problem... However, I hope the alternator is the fix for your car. I suppose a leaking bridge rectifer could cause the discharging battery. Keep us posted. By the way I have found that Napa parts have been reliable and generally cheaper than Kragens in most cases. Online ordering has been very kind to my wallet, but you have to have time and some planing.

[Grumpa72]

13.73 volts MAY NOT be bad. What is the factory spec? Usually the manufacturer will give a range of, say, 13.9 to 14.3 volts or something like that. I would call the service department and ask them for the battery specs. However, since the batteries operate at 12+/- volts, it should get a full charge from an alternator putting out 13.73 volts. Get another test from a different shop, Advance Auto, Auto Zone, etc.

Gary

[lenore]

He already bought a new alternator. What a bummer.

[carguy07]

He said Amps not Volts.

[lenore]

He said Amps not Volts.

Yes he did, I just assumed he got it wrong

[carguy07]

He said Amps not Volts.

Yes he did, I just assumed he got it wrong

You're probably right. 13.73 amps would not do you much good.

[keridrives]

In August of 2006, I posted a question on this forum about the battery going dead on my 2000 RX300, thinking I might be able to fix the problem on my own. But after replacing the battery and getting some helpful advice, I finally relented and took the car to my dealer. He replaced the body control module for $812.47 and that seemed to fix the problem.

Fast forward to this past weekend...another dead battery. The battery is, of course, only 16 months old (10K miles) and I didn't do anything that would have caused the battery to run down. I've since recharged the battery and attached a trickle-charger but it appears to be continuing to have to add juice to keep the battery charged (in other words, it appears that there's an on-going loss of current somewhere). Given my last experience, I can't help wondering whether this has to do with the previously replaced body control module and, if so, did they just correct a symptom by replacing it when something else was actually causing it to go bad and it's killed the new one now?

So...what to do now:

Take it back to the dealer?
Buy a body control module myself, replace it and see if that fixes the problem?
Run some tests to verify the amperage leakage?
Start looking at the 2008 models?

Thanks for any suggestions you can offer.

Bob

I had the same problem recently with my 2000 RX300. When it got cold, suddenly my battery would drain completely. My husband checked the battery to make sure that was not the problem, using his digital mutlimeter. He checked to verify it was not the alternator either, and then proceeded to check each fuse to find where the drain is occurring.

He has isolated the problem to two specific fuses, 15 and 16. One controls the dome light and interior lights, and the other one controls the ECU. Based on everything I've read so far, here and other web sites, I'm thinking it has something to do with the door(s). The reason I think that is that we have a stubborn lab that refused to get out of the car one night. We left the door open (after turning off the dome light) for only about 10 minutes before he finally decided to join us in the house. The battery was dead. I usually drive the car by myself, and other than open the rear hatch, rarely use the other doors for anything. Almost every time I use that same door (backseat, driver's side), the battery dies.

We are going to assume it has something to do with that door. We're going to try the door lock mechanism and anything else connected to that door. 'm tired of recharging my battery. The weird thing is that it runs fine for weeks, but then suddenly it starts having issues again. At first, we thought it was the cold weather, but then it seemed connected more and more to whenever I had the occasion to use that back door.

I'll let you know if we find out anything.

Keri

[Montalvo]

Well, first an update on my replacement of the alternator. I put the new one in since my last post and haven't had a problem with the battery going dead since then. And yes, I should have said volts, not amps (pretty embarrassing for a degreed engineer!). According to the installation instructions on the alternator, my old one's voltage tested within what they called an acceptable range, although who knows whether those crack mechanics at Wal-Mart tested it correctly.

So, is my problem fixed? Well, I thought so until last night when my car alarm began sounding intermittently in the garage for no apparent reason. I put my key in the ignition and that seemed to keep it from going off. Could it be related to this problem? Did I screw something up while replacing the alternator? And if so, why didn't I have a problem until just last night? I followed the installation instructions carefully, including disconnecting the battery during installation, but with all the electronics in even "old" cars like my 2000 RX, it's possible I messed up something.

Regarding Keri's problem with an occasional dead battery, you might want to read thru my posting from 2006 when I had a similar problem that turned out to be the body control module, finally diagnosed and repaired by the dealer.

Bob