Guys & Girls,
New to the site but in desperate need of some help!
This morning the Mrs 2002 Mini Cooper would not unlock using her key, then the car would not turn over. Since getting home I have changed the battery in the key fob, it did not work. I checked the ignition, it did not make a sound no turn over at all nothing. I checked the battery with battery tester, no output, it was dead. After connecting a battery charger jump set, I heard a humming sound from within the engine as soon as I connected negative I continued and and then checked the key, it worked and unlocked and locked the central locking, I started the car and no problem. Took the car out to boost the battery about 4miles round trip. On getting back I turned the engine off and heard the same sound as before, telling me something was draining the battery. I checked all fuses but nothing stopped the humming sound, I could not find anything and on checking battery I was good. I have read that this is common, but only for about 4/5 mins then stops. I read that you should disconnect the neg on the battery, and reconnect. This stopped as soon as was disconnected, but came on as soon as connected. I left it for an hour and then went back, the battery is dead again and it has shut the car down again from using the key. Too dark now to look but in 12hrs I'll be back out. Any advice as confused if this is a shorted battery, a short circuit or so blown fuse or something else.

 

Bet you are hearing the ps pump running....the humming sound...
Common issue when the electronics in it fail...
It is a BIG DC powered motor....
Also look under the hood....the radiator fan is also electric...that is the sound folks sometimes hears for 4-5 minutes as the car cools down...then normally shuts off...it is possible a relay got stuck/failed, leaving it running.....pretty easy to look at the radiator fan to see if it is running.....

 

P.S.
It normally takes about 15 minutes for a car battery to fully recover from a start...and MUCH LONGER (IF EVER...they sometimes fail internally when drained)...say hour or two or longer from being dead...

 

When you say that you've checked all the fuses, do you mean that you've pulled them out to see if it would stop? What about the relays?

The best way to check for a drain is to disconnect the negative connector on the battery and connect your multimeter between the connector and the pole, wait a bit (usually the security system on most car will take some power after the connection is made) and check for an amp draw, key out of ignition of course. Then pulling one fuse at a time, as well as the relays, once the amps drop to a normal level (not sure what it is on a Mini), you'll know where it's coming from.

I had a 2amp draw on my 95 Tercel and it was after testing it and pulling the alternator fuse that I've found it (Faulty rebuilt alternator).

 

Thanks ZippyNH and Da_Ghost for your advice, been out this morning and miraculously she was still dead, after jumping her she continued to make the same noise and tried R3,R4 with no success, she has has a new PS Pump put in just a few weeks ago. Whatever is drawing from the battery is drawing a lot of power as the battery died quickly. I'm confused but that's not hard, I'm no mechanic but I do understand electrics a little, the battery when charged holds its power well when disconnected from the car so it's not the battery, when fuses are removed and relays the noise continues however I have not done this in reverse so as to see if it's removed then start her up, shut down and see if the noise continues. I think it's time to get the man with the van round to see. Will keep you posted.

 

Ok so still investigating the mystery of the sound, changed the battery over today but as soon as neg is connected the sound comes back. Sent the mrs to buy a multimeter so I can investigate further. Eliminating the problems is not so hard, finding the problem is harder. This guys is a great welcome to civvy street, my best friend is now a Haynes manual and it seems I feel I have been imprisoned for 22yrs. A steep learning curve, but I will find the answer to the problem.

 

Zippy can you tell me if I am supposed to have a fan covering the power steering pump? I have looked on both minis and neither have one, the videos on YouTube all have them but don't say what mini it is. The manual tells me to take the fan off to access the electric connections to see if the fault is there. I believe it's the ps pump as you mentioned, the mrs failed to tell me it was a reconditioned pump not a brand new one.

 

Should be a fan...looks almost like a computer fan....on a bracket...has an oval plug with 2 pins...
The fan often siezes....which (if the updated wiring harness, available from about 2005+ production date cars and on any mini modified under a "campaign") then blows a 5 amp fuse, which know kills a relay that kills the radiator fan...leading to overheating when stopped...
The updated harness simply changed which fuse blows....
The rebuilt ps pumps have been an issue for many...but often have warrenty...but swapping 2-3 pumps to find one with good electronics ( the physical oil pumping part is replaced, as are the brushes, but the controller and motor are just cleaned) often costs as much as just buying a new one if you are not diy'ing the pump changes.....
I know the mini s r53 and r50 cooper both have them...not sure about the ONE..._they were never exported...but seems to share 99% of the parts...mostly just a stripped base with a smaller motor from my understanding to lower the $$. Some early 2002 cars WERE a bit different..mostly suspension parts though....

 

Had the AA out today, confirmed a short on the power steering pump somewhere, car off to garage this week, mmmmm the cost of running a car just increases.

 

Sadly enough, that's the reason I've paid more for a brand new pump. (Saw a couple of stories about rebuilt pumps over the years)