0.16a Battery Drain with key out

[Ajax Lexus]

0.16a Battery drain with key removed, courtesy lights off. Removal of 10a Dome fuse stops the drain. Any suggestions?

[steve2006]

Hi Ajax and welcome to the LOC.

If your car has an alarm/immobiliser fitted bear in mind it can take a while until this “goes to sleep” so current draw will remain higher until this happens.

The dome fuse feeds various components including steering tilt and telescope and the door locking system, I did try to find exactly what on a search without success but basically you will need to do is isolate each component until the current draw drops.

[Malc1]

Welcome Ajax .  I'm intrigued .  you have a very very early surviving Ls400  .  can you tell us more about your incredible car ?

Malc

[BigBoomer]

I don't know the LS400, but if it's anything like my 2004 LS430 then you need to leave the ignition off for about 15 minutes before the current draw drops to a steady state.
After shutting the ignition off the car continues doing stuff as it goes through it's shutdown procedure, which I assume is all the various computers getting themselves synchronised and into the correct state.

I was testing for what was draining my Battery during the COVID lockdown and I found that it drew between 0.1A and 0.5A for at least 15 mins after ignition off, after which it dropped to just 0.02A which seems to be the steady state draw. I then switched off the SmartKey system and tested again and the steady state draw dropped to below 0.01A.

[Malc1]

1 hour ago, BigBoomer said:

which I assume is all the various computers

but this is a 1991 car with very limited technology computerwise compared to even your ancient steed George  😉  .  sorry I jest ................. Ajax has gone to sleep methinks  !

Malc