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VW Passat - battery drain

A friend has a 2001 2.0L petrol Passat with a problematic battery drain.

With the alternator connection removed from the battery, the doors closed and locked (and the alarm set) there is a continuous 0.2A (200mA) drain from the battery.

He has removed all the fuses one by one and the drain remains at all time. i.e. none of the fuses removed stopped the drain. That either means that it is not on one of those fused circuits or there is a back feed through a second fuse.

Putting the fuses aside, my immediate thoughts were the radio (although he's certain that's through the fusebox), so it should be detected when the fuse was pulled or the other possible option is the alarm.

Could the alarm be taking more current than usual (dying or dead back up battery taking a high charge)? But, being an alarm there is no information on its circuits (or even location) in the manuals available to the public, so we don't know where to start!

Has anyone else experienced this problem? And can you give him/me some pointers before we blow a large amount of money at an auto electrician!

Failing that, can anybody recommend an auto electrician in the Swindon area?

Cheers

Peter

Reply to
puffernutter
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Friend had a Citroen with similar,flattening the battery overnight-occasionally. On warranty so back to the main dealer on several occasions. Checked alternator-ok, and changed battery twice. I suspected the alternator was stopping at a position where there was a back feed causing the current drain, but not every time the engine stopped. He suggested this and they then changed the alternator, congratulating themselves they found the problem. DaveK.

Reply to
davek

Try unlocking the alarm. Erwin will sell you th ereal electrical diagrams.

Reply to
Duncanwood

You didn't say if the drain remains with the doors unlocked/ alarm off. If the current changes it would indicate alarm/locking fault. Had a faulty central locking module causing the same problem on a Honda recently, so it does happen.

Reply to
John

An alternator doesn't have an armature so if there was an intermittent fault it had nothing to do with where the alternator stopped.

John

Reply to
John

Reply to
Duncanwood

Thanks for the various suggestions. It looks like it may be beyond the home auto diy-er, so can anybody recommend an auto electrical specialist in the Swindon/North Wiltshire area?

Cheers

Peter

Reply to
puffernutter

There's a difference between an armature and a rotor.

John

Reply to
John

Reply to
Duncanwood

The message from Duncanwood contains these words:

Not bad for an armature!

Reply to
Guy King

Well I've never seen an alternator with an armature.

JOhn

Reply to
John

In a car alternator it's the staionary bit the rotor spins inside.

Reply to
Duncanwood

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