That's the wierd thing it isn't on. First thing I knew of a problem was when the instruments went appocalyptic and eventually the car wouldn't go. Initially I though it was because I had been wearing bigger than normal shoes and had kicked something loose in the fueses. It was only when I got a multi meter on it I realised there was a problem.
With a fully charged battery showing 12.9 volts off the car, with the engine running, no fans, heaters, lights or stereo it goes down to 12.4v.