Power draining away over few days

Forgot to mention I already bought a new battery in case it was a bit dicky...

A car battery can look flat, even when nearly fully charged, if it is asked for a relatively small discharge - a coating builds up on the plates. If a surprisingly short charge (which knocks the coating off) restores things then this is your problem. Stick an ammeter into the circuit and see what's leaving the battery when everything should be off. I've known this problem to be caused by a radio left on overnight and by a boot light which didn't go out when it should.

Ian

Interesting - one thing I have noticed is that when the ignition is off, I can hear a very high-pitched whine coming from the engine bay - the area of the alternator / water pump. When the ignition is turned on, but the car not started, this whine goes away. I did check all the boot lights, radio, glove box light etc. So I wonder what the high-pitched whine is?

The alarm and immobiliser will likely still take current when not on.

High quiescent current draw is often caused by a faulty alternator rectifier - although the alternator will still charge at reduced efficiency.

on 28/10/2007, GTS supposed :

A hot cooling system venting air perhaps?

Some electric cooling fans can run a while after the ignition is turned off, could that be you you can hear?

:-)

So I wonder what the high-pitched whine is?

try leaving yer missus at home !

No definately nothing obvious - and as stated, the whine goes away if the ignition is turned on. It is very high-pitched, similar to the sound made by PIR cat repellers (that are not meant to be heard by adult humans)

I did wonder if it was the regulator on the alternator. I guess I should try this first, but it seems the regulator and brushes cannot be purchased separatly, but I may look in breakers yards... Also the Haynes manual says the alternator *should* be removed to replace the regulator, so not sure if it is even possible to do this with it in place...

It would be usual to work on the alt. on the bench, but first, why not just disconnect the alternator? if the battery stays up and the whine stops, you have found the problem.

Have you checked all the earth cables are good, and the connections are also clean? Assuming you have, disconnect the battery for the time you leave it, then reconnect and try starting. Assuming it then starts OK, you definitely have a leak somewhere. Also, you might see a spark when you reconnect the battery, this will give a clue that there is a drain.

That kills those suggestions....

I wonder then if it might be a bit of moisture which has got into somewhere it didn't ought to be, causing a relay to chatter on and off at high speed?

I had a diesels EGR valve make this sort of noise for a while after the ignition was cut sometimes. The noise source was not easy to find.

It wouldn't be the regulator but a diode in the rectifier. If one fails short circuit it will cause the alternator to draw current from the battery with the engine not running, as the output of the alternator is connected directly to it. Disconnecting the output wire(s) from the alternator overnight or whatever would prove it. Another way is to wire a

21 watt stop lamp etc bulb between the output and battery poisitive with the output disconnected - ie in series. If the bulb lights up you have a problem.

I'd not attempt to replace the rectifier pack in situ as it is has soldered connections - and requires a pretty meaty soldering iron. It will be available as a spare - but I dunno where from.

Thank to all for the good tips. I will try disconnecting the alternator to see if the power still drains away. The only problem with disconnecting the battery, is the insane key-waggling I have to do to reset the immobiliser, as each time it prevents the car from starting after a disconnect. I found out how to do the key waggling on the internet, but have not found how to disable the immobilser permanently...after all, I don't think my old banger will be much of a target for theives!

I'm not so sure. Since most cars have immobilisers these days that can't be got round easily, those without become targets for joyriders.

I am not familiar with the Rover 220 1994 spec

When you hear this whine, is it: head under the bonnet ? or sitting in drivers seat ?Does it have an ultrasonic volumetric intruder alarm ?

Just wondered about this when you said it goes away when you turn the ignition on.

Alan

I have used these guys on a few occasions:

AIUI They are "Trade Only" but they "never like to say no ! " :-\)

Alan