>>I have a Toyota Avensis. The battery ran flat and I needed roadside
>>assistance to start the car. The AA man tested the battery and said it is
>>leaking to earth (to the body). He said it could be a bulb on in the glove
>>box or whatever. I have checked and found nothing obvious. I did change
>>some bulbs in the clock displays recently.
>>
>> The man had specialist amp clamps to see if the electrical system was
>> leaking from the battery. I only have a multi-meter. Anyone know how I
>> can test using this? I can remove fuses and isolate the circuit and test
>> which circuit is the problem.
>
> As Rigger and Retired VIP mentioned, some multi-meters have a limited
> capacity to measure amperage, and clamp type multi-meters are not very
> accurate when measuring low amperage.
>
> Most cars will indicate some "leaking too earth" because some electronic
> components draw power all the time, even when the car is parked and the
> engine is not running. For example, the engine electronic control unit,
> clock, and radio draw some power to retain memory. You did not mention
> how long the car was parked, but if it has been parked for a long time, a
> dead battery is not unusual or necessarily an indication of a problem with
> the battery or car's electrical system.
>
> To diagnose whether or not the problem is due to excessive current draw or
> a bad battery, you will need a multi-meter with the ability to measure at
> least 1 ampere, preferably 2 or 3 amps and you will need the specification
> for your car's current draw when the ignition is off.
>
> An easier and less expensive approach would be to take the car to a place
> that can load-test the battery and check the car's charging system. The
> most likely cause of the problem is a bad battery, even though it is only
> 18 months old.
Thanks, the AA man said the current draw was too high and was similar to a small warning bulb. The car was not used fro 4 days. I have previously left it for two weeks and it has started.