This 1999 Lexus ES300 was sent to me because that battery would go dead after several days of sitting. I checked with the customer to make sure he had the radio code of needed. Thankfully in the end we did not have to have it. Next, I connected my multimeter to the engine and to the negative battery post. I already had the leads set up for reading dc amps and at the 10 amp location. The initial amp draw was 1.23 amps.
After a few minutes it went down to .53 amps as different modules went to sleep.
Finally after leaving the car alone for about half an hour it settled down to a .10 amp draw and stayed there.
I was very lucky on this one. The first fuse that I pulled dropped the drain down to .02-.03 amps.
I checked the fuse designation and went to my wiring diagrams to see what all was attached to that fuse.
The system drain with the fuse removed.
I found out that one of the things this fuse supplied was the memory power seat. I have seen a lot of power seat switches get stuck and cause drains and blow fuses. I went right to the driver’s power seat to inspect and this is what I found. A button stuck in.
A light touch with my screw driver and it popped right up. I worked it back and forth several times. It never stuck again.
The fuse back in the fuse box and the drain was still at .02 amps. I advised the customer of the situation and he stated that he would just keep and eye on it to see if it would stick again.
That was about four months ago and I have not heard back from them.
Lawrence Lexus in NJ tried to sell me a new alternator for $440.
I have a ’99 Lexus es300 – my mechanic could not find the problem but assured me it was not the alternator. After replacing several batteries, AAA had given up on me. No problems for over a year now.
You hit the nail on the head (or should I say button!)
I found the same. Button stuck. Hope it fixes the problem. Three batteries from Costco – all warranty – they were beginning to balk.
55HUGE Thank You !
Found same symptom on our 97 ES 300
Seat memory SET button stuck down
Freed it + add tiny bit of penetrating oil
Button moves freely
Hope slight battery drain is now gone. Will lv car and ck back in a week
SAME THING!! 4 years and many batteries later, my mechanic could not figure it out – Lexus dealer in Houston did! Coke spilled on the buttons stuck them in engaged position….
You are the master!!! 4 batteries and 1 altenator later I find your post, you nailed it spot on, exact same button, stuck in, killing the battery- thanks a ton, thanks a ton, THANKS