Boot Light Issue

[Paul_Derby]

Hi folks

I have a 2001 LS400 in generally good condition.

I left the boot open for 4 hours today, and on my return the Battery was flat - I couldn't operate the remote unlocking, and no dash lights would appear.

After charging the Battery everything was fine. The genuine Lexus Battery is a year old and was tested tonight and passed as good - held up well on the high current test. The alternator tests good too.

My question is: how can a 6watt bulb drain the Battery in 4hrs? 6 watts is roughly half an amp, so that's a total of 2amp-hours drawn. Surely the Battery can take that.

Further investigation showed that the "residual" current being drawn from the Battery with nothing turned on in the car is around 100mA (presumably all the computer chips, monitors, alarm unit etc.) But open the boot and it jumps to 1.8A. So, take off the 500mA drawn by the bulb. What's drawing the other 1.2A?

Anyone know what else comes into play when the boot light is triggered?

Regards

Paul

[tartje]

Is there a light on the dash which illuminates telling you the boot is open?

I know also that alarm systems piggy back that switch also, which completes the circuit so that if the alarm is activated, it sets the siren off.

Perhaps a combination of those things all add to the increased power drain.

[Paul_Derby]

Is there a light on the dash which illuminates telling you the boot is open?

I know also that alarm systems piggy back that switch also, which completes the circuit so that if the alarm is activated, it sets the siren off.

Perhaps a combination of those things all add to the increased power drain.

Thanks Tartje,

There is a dash lamp but it's not lit unless the ignition is on.

It's all very odd, but some things we just have to accept I guess...

I've learned my lesson - don't leave the boot open!

Paul