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[zirk]

I have already disconnected battery from car and tested it for a few days and its ok.  So its the car somewere but where?  Over the next few days will check the car over.  If I have a scale on my multimeter of 200mA that should pick up the drain??

Wouldn't have thought a current drain less than 200mA would flaten the battery, hopefully your meter go's higher than 200mA otherwise its not going to be much good to you, you may need up to 10A or a Clamp meter.

No nothing about the 2.2Dti, but just a thought, an issue on the 2.5TD's is the Glow Plug Relay gets sticky / arch's itself causing total flat battery, does the inlet manifold stay warm long after your switched off.

Chris.

[Andy H]

I have already disconnected battery from car and tested it for a few days and its ok.  So its the car somewere but where?  Over the next few days will check the car over.  If I have a scale on my multimeter of 200mA that should pick up the drain??

Your multimeter should have a fuse to protect it from overcurrent on the Amp/milliAmp settings. I have wasted hours looking for a current drain using a multimeter because the first circuit I tried blew the fuse (and I didn't notice). The multimeter worked fine on the voltage and resistance ranges which is why I didn't realise that the current ranges weren't registering 

[Dave DND]

You will need to take some accurate current readings using a clamp meter, a multimeter would not be good enough to perform this sort of diagnosis

[Kevin Wood]

Just to say, most clamp meters only work with AC current and we're talking DC here. Affordable clamp meters that do support DC current measurement usually have pretty poor resolution at low currents so if the quiescent current is very low, you may not be able to see it with a clamp meter.

Normal multimeters have their own problems in that they need to be put in series with the load, so the battery terminal needs to be disconnected and the meter connected in series. The battery will be capable of delivering several hundred amps and the fuse in the meter won't blow in time to save it in all circumstances. So, if you want to measure it using a conventional meter switch everything off, disconnect the battery, close all doors, connect the meter in series on a high (10 Amp) current range and immediately disconnect it if it goes overrange.

Let the current settle for a while (it can take 15 mins for the accessory timer to cut the supply to some parts of the car) and back down the ranges on the multimeter until you get a sensible reading. It'll probably settle to a value in the region of 50-80 mA. Much more than 100 mA and you're going to have a problem with the battery draining.

Disconnect the multimeter as soon as you've taken the reading.

There's some more detailed info here: http://www.omegaowners.com/forum/YaBB.pl?num=1225724099

Kevin

[andy4775]

Some really good points here lads, will work on the car over the week end.  I will check that the fuse hasn't blown in my multimeter first tho.   Thanks.   Will let you know what the outcome is.

[andy4775]

With all your help and advice I have finally found the drain on my battery it was in the relay and fuse box in the engine compartment, when I removed the 10A fuse the reading fell from 0.26A to 0.03A.  The fuse was along side two blue relays and the handbook says that in this box the relays and fuses are for the preheating system and fuel filter heating as well as others. Left the fuse out and everything seems to be working but the test will be in the morning when I start from cold.  Any idea what is wrong, now that I have narrowed it down a bit, is it just just a case of changing the relays.  I suppose I could do with a diagram of the electrics?

[KillerWatt]

I have already disconnected battery from car and tested it for a few days and its ok.  So its the car somewere but where?  Over the next few days will check the car over.  If I have a scale on my multimeter of 200mA that should pick up the drain??

Set your meter to the 10A range, and plug the red test lead in to the socket that is marked up for measuring current.