Battery light

[Brenner5]

I have just got my car back on the road (91 e30 325i) and the battery light is always on apart from when the car is actually started.

i have put in a new battery

when the car is on it charges the battery but when left off overnight it kills the battery

i have yet to check the alternator charge with a volmeter but what else should i check for?

boot light is off when boot is closed

[kam-325i]

check for a drain on the battery without the keys in the ignition.

[Brenner5]

Are there any other reason why the battery light is on?

I'll try to find the fault tomorrow..

[jmc330i]

the battery light is always on apart from when the car is actually started.

The red battery light will come on when the battery is not being charged (duff alternator, fan belt gone etc) - its a warning that the battery is not charging.
The light will come on with the ignition and stay on until the engine is started and the alternator is charging the battery.
Your battery light is working fine, unless Ive misunderstood you - which is quite possible as its late and Ive been awake since 5am


You mention the boot light, but also try the glovebox light - the switch and bulb holder are an all in one thing and are often the cause of mysterious battery drains.

As Kam said, check for a drain - pull fuses one at a time whilst keeping an eye on the meter.