A couple of weeks ago the battery in the Mini started draining fast. Thinking it was a battery that had gone bad I took it in to be tested and they said it was a bad battery so I got a new one. Couple of days later it was dead also. So I took it in to a local auto repair shop. They kept it over night and tested the battery in the morning and it had drained considerably. So something is draining the battery. I suspect a short somewhere. The auto repair shop will be trying to trace it down but I thought I would post a query on this forum to see if it has been a common issue and if so, where I could steer the shop to look. It's a 2004 Mini.

 

When troubleshooting this in the past, the easiest way I found was to put my multimeter in line between the battery and battery cable (high amp range) and start pulling fuses until the current dropped off. A schematic is needed of course.

One time on a Ford Ranger I found that the glovebox light was stuck on, draining the battery overnight. Glovebox door needed adjustment.

Whatever is draining your battery is something like that, that always has battery power even when the key is off.

 

Ok got the Mini back. THe mechanic went through and started pulling fuses and checking the draw. There was a 1.5 amp draw after 30 minutes. The culprits appear to be fuses F24 and F27 which deal with the radio and security. After those two were pulled no more draw. But when the fuses were re-installed everything went back to normal. No more draw. It appears that when the two fuses were pulled, something was re-set, thus stopping the draw. Anyone heard anything like that?

 

Sounds like a Power Down Reset was done on the radio and security systems, like you’d do for a computer running Microsoft Windows. But that’s a rant for another time.

If it happens again, I’d pull the radio fuse for a week or so and see if that cures it.

I don’t know if the car will run with the security fuse out.

 

Thank you for this. Just replaced my battery with a 2.5 lb lithium and after installing my new gauges. It’s been draining too.

either bad battery or i messed up the wiring somewhere.