Seems like I got the basics in the title, after a weeks holiday I came back to a flat battery, it is 4 years old, so perhaps past its best, but I investigated and there is a 140ma drain with the car locked and alarmed, and left for 20 minutes with the bonnet lock closed with a screwdriver, but the bonnet up.
Pulling fuses makes no difference except the ODB fuse, which drops the drain to a more reasonable 50ma.
I also get a few beeps from somewhere in the engine compartment when I pull this fuse.
So what is on the other end of the OBD fuse? I assume an OBD cpu, I will start looking this up, but anyone who has been here before, I'd be glad of any assistance