Battery drain? (semi-isolated)

[Rocket Science Racing]

With the problem fuse pulled (drum roll please)...56mA total! Hooray!

This breaks down as follows: 17mA for instrument cluster, 13mA for radio,
22mA for central locks and 4mA for ??? (probably within the limits of
measurement error).

And the problem circuit is (another drum roll)...the seat heaters. 510mA on
that circuit alone over and above the 56mA normal load.

This sort of explains something I found when I was going through the car
after buying it used a few weeks ago. The seat heater connector under the
driver's seat was disconnected. I connected it thinking it was just "one of
those things". Everything was good until I parked the car for a few days to
replace the B2S1 O2 sensor (what a pain!) Dead battery ensued.

Excess drain with the seat heaters all hooked up is 510mA. Excess drain with
the driver's seat heater disconnected is 14mA. Weird. Any ideas are greatly
appreciated especially if they reduce the required study of my eBahn wiring
diagrams.

Thanks,

Scott
2001S4m