Battery Running Down With "Everything" Off ?

Even with the radio off, it still draws power in order to retain memory for the station pre-sets. Same is true for the clock.

Yes, or it would blow the fuse for the circuit in question.

The Electronic Control Units (ECU) for the engine and transmission also draw some power to retain memory settings.

If the car is within reach of an outlet, you can get a very compact automatic trickle charger that mounts under the hood. When you park it for any length of time, you can plug it in and the charger will automatically turn on and off as necessary. Auto parts stores or Sears Automotive sells these for under $40.00.

If you leave a battery in a discharged state for a long time it will become sulfated and will lose its ability to hold a charge.

keep disconnecting things till the draw stops, first thing I would pull is the connectors of the alternator.

mrcheerful

For sure...

Well, that's like about 3 watts (250 mA @ 12 V) which is quite a lot for those conditions. could there be a 'service light' (maybe under the hood) which isn't getting switched off when the hood closes?, possibly one in the trunk?...in the glove box?. Do you have a remote engine starter? (sometimes those seem to draw a little more than they should)