HELLO NEW USER HERE!
I have a 1998 Lexus ES300 (v6 model) and recently the battery has died on me a few times. I charge it overnight and after a week or so the car is dead completely. Sometimes after 2 days of not running the car it also dies. I have no lights on, nothing plugged into the charging port and I even go to the lengths of double checking my doors are closed properly because the front doors have an interior light that shuts off when doors close. I've taken it to see three mechanics, and none can find what's draining the battery. They've pulled fuses and used a multimeter and still no luck. They even double checked my alternator, and it looks fine. The battery is even brand new (Feb 2025). The only advice they've given me is to start the car every day to atleast have the alternator charge the battery. I only use the car to go to and from work because I am afraid I'll get stranded somewhere if i decide to go anywhere far. I've already gotten scammed once and I'm desperate for any help or advice. Its a slow drain that is killing my car overnight and I really want/need help figuring it out (WITHOUT GETTING SCAMMED)

This is the car, I've blocked out the license plate for my safety,
. It's my first car and I would like it to last with me for a while.

 

This is a relatively simple explanation of how to find parasitic draw.


For your car typical draw after the car goes to sleep (explained in video) will be about 15 milliamps.

 

I watched both mechanics i went to do the whole fuse thing for the parasitic draw and they still couldn't find it. What else could be the problem if its not the fuses?

 

Fuses don't draw power the circuits they are in do. The problem is one or more of those circuits regardless of what your mechanic did or did not do.

 

So even if they pulled fuses and nothing changed on the multimeter what could be draining the battery? should i just pull all interior fuses out of the circuits and the drain will be gone?

 

Have to pull fuses until the drain stops not just interior fuses. Did you watch the video? Does your car have any aftermarket addons like remote start? Security system?

 

Yes I did. Except when they pulled fuses nothing drops significantly to where they could find the drain. I'm planning on showing them video you posted here and see if they can recheck with the multimeter again. Because when they did it the first time they pulled fuses one by one; instead of taking it all out.

 

One at a time is the correct method otherwise you don't know which circuit is at fault. I'll ask again any aftermarket stuff installed? What was the current draw with the car in sleep mode? This process is not rocket science it only takes a few minutes to narrow down the general circuit that is drawing too much power. Assuming that is the problem and not a faulty alternator, bad grounds, bad battery terminals etc.

Probably should not go back to the same mechanic that can't do basic checks.

 

Nothings been installed on the car. I'm not sure on the current draw while its in sleep mode because both mechanics used different types of multimeters and I can't remember the amps for the two. All they told me was that since nothing is changing when fuses are being pulled, was that it could be a light that is on somewhere and we can't see it which is causing a slow drain. The mechanic i talked to yesterday said because the drain is so slow he can't figure out what it could be.
I originally was going to call a toyota/servco lexus dealership to see if i could get in contact with someone to find the drain. this whole thing is just stressing me out because it only started recently.

 

You can easily do a current draw test yourself with a $30 multimeter.

 

yeah ill probably buy one, currently i have the battery itself charging. I just can't figure out why BOTH mechanics couldn't find the drain; like isn't that part of your job--to repair cars? I'm so tempted to disconnect everything at this point. I read reddit articles and found videos and it could be anything from a hoodlatch light to a glove compartment light. Literally stressing out

 

Most common cause is water intrusion especially if the water sits inside a connector. Any leaks into the trunk or sunroof drain leaks? And sometimes (rarely on these cars I think) modules go bad and draw too much power same with the stereo system. Your car isn't super complex electrically won't take long to find the general circuit causing the issue.

.... to answer your question why two mechanics were unable to track down the problem, most are wrench turners and have a "swap till you drop" mentality tracking down parasitic draw is a different animal. Most dealers won't know what to do either they'll just throw parts at the problem.

 

My car doesn't have a sunroof or any leaks in the trunk. The only leak it has is an oil leak. (nothing major but will fix soon)

How do I know if the stereo system is causing a drain? I'm assuming the multimeter check thingy is needed? I always turn off the radio/stereo before shutting the car off; but there is a red blinking light on the security system near the stereo too; OMG COULD THAT CAUSE A DRAIN TOO? D:

Also yeah thats why I'm kinda iffy about going to a dealership because I know it'll end up being overpriced. But this drain is keeping me from getting to work on time; I even bought a portable jumper and jumper cables because I have a feeling someday if this doesn't get fixed I'll end up stranded somewhere.

 

Flashing security light is of course normal. Can get a miltimeter for as little as $15 but I recommend something more respectable. The price of this is about 10 minutes of a mechanics time.

Turning off the stereo (or not) doesn't make any difference.

 

THANKYOU FOR THE AMAZON LINK (literally adding it to my cart rn)

If I still can't find the drain even after following the video you posted earlier using my own multimeter, what should be my next step? You mentioned the modules earlier. (i have no clue what that is)