What's causing my Mercedes battery to drain?

My 2004 Mercedes-Benz M 270 CDI is discharging the battery within two hours when parked up. It has a new battery, the sam units, alternator, interior overhead lighting, door sensors and dash clocks were all checked and none of these seem to be the problem. Have you any suggestions to what may be the cause of this?

Shane Evans (Cork)

Nov 2012 Filed under: fault

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Expert answer

Hi Shane,

This is a job for a really good auto electrician to find, but we do know that some Mercs have such an issue caused by a CD changer. The only way to stop it appears to be physically unplugging it from the car! Take the car to an auto electrician and tell them that and they may find a way to install a switch for it or to fix it properly...

Hope that helps

Shane O' Donoghue - Complete Car Adviser
@Shane_O_D