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[Chopsdad]

A friend of mine has an M Reg 2.0 CD that keeps draining batteries.

He has fitted a new one but it's dead already.

He thinks it's a faulty alternator but any other places to look first :-?

[TheBoy]

A friend of mine has an M Reg 2.0 CD that keeps draining batteries.

He has fitted a new one but it's dead already.

He thinks it's a faulty alternator but any other places to look first :-?

Stick a meter on it, that will tell you...

[Danny]

not an omega, and possibly completely unhelpful but a story about a saxo that used to kill batteries, fault was found to be that something had shorted meaning the heated rear window was permanently on

[ffcgary1]

Check that all the interior lights go off when doors are shut, inc the boot/tailgate lamp AND the vanity lights on the sun visors are pushed up properly.

[Kevin Wood]

fault was found to be that something had shorted meaning the heated rear window was permanently on

I've had this too. Many accessories are powered directly from the battery via a relay. If the relay contacts weld closed, battery goes flat.

First stop is to measure voltage when running and identify if the battery is charging.

If that looks OK, check the current from the battery when idle.

Use a multimeter with at least a 10 amp range in series with the battery. Put a headlamp bulb in series with the multimeter to protect it in case something draws a huge current. Leave the car for a few minutes with everything closed (except the bonnet!) so that it's stable, then measure the current, moving down the ranges on the multimeter as required. Normal standing current should be tens of milliamps or less.

If you've got a drain problem, keep the multimeter connected and go round unplugging fuses until you find the one that's passing the current. That should narrow down the problem to a few circuits.

Kevin

[Chopsdad]

Check that all the interior lights go off when doors are shut, inc the boot/tailgate lamp AND the vanity lights on the sun visors are pushed up properly.

That's the first, last and only thing I checked Gary  Guess I'll have to get the Mulitmeter out

[VX1]

Is the car still turning over but a bit sluggish? and does it eventually start? If so then this will be the alternator same thing happened to me before the battery light came on changed the alternator and problem solved no more dead batteries.
Hope this helps.