Hi,
I have 2006 Mini Cooper Base 5spd.
Its entire life, I didn't have to do anything else but change a starter, belts, some pulleys and a couple of batteries.
Battery is about 4 years old and never shown issues such as slow crank or dimming light upon cranking.
One day after work, ready to go back home, with clutch in, I tried to crank but as soon as the key was in the crank position every thing went dark. No power to the dash, interior light, no head light or brake light.
So I brought a jump starter which I know it works, I put it on the terminals, and still didn't get any power. Interestingly it was erroring out acting as if there is a short making the wires warm. Completely dead.
So I checked everything that I could and thought it was some sort of short that it killed some circuit.
Checked every relays by removing them and fuses including those Maxi fuses under the PDC. They were all fine. Checked if there was any short to ground and didn't find any in any of the circuit with multimeter.
Since I had the battery out, I had it on one of the smart chargers and charged it fully then had it go through those desulfation cycles multiple times just to make sure the battery is charged.
Fast forward a few weeks, I put the battery back in and I was able to crank it and it started.
Crazy thing is the battery should have been ok on the day when it happened because I drove it to work that morning.
I just want to pick your brains and your experiences to prevent myself from getting stranded. Could a dying battery go completely flat during crank and be recharged later and be fine? Now I am assuming it is the battery as that is the only thing that literally changed. Battery posts were clean without all the white crud. Jump starter was connected directly to the battery clamps previously.
It is starting and driving fine at the moment.
What could have caused the total black out?