Obtained from our American Chums at http://www.corrado-club.com
"An additional entry for your known problems list.
I have a 1990 G60 which has drained the battery when
parked since day one. What I eventually discovered
is that there is a power window relay control unit
mounted to the left of the left rear passenger seat
which has a connection to the door switches (why?).
I observed that when the unit is first connected with
the doors CLOSED there is no power drain. However, as
soon as a door is opened a relay engages inside the
unit (you can hear it click in) and from then on there
is a consistent 100mA drain on the battery. You can
only release the relay (and the power drain) by
unplugging the power feed to the relay module. This
power drain is not a problem if the car is driven
regularly, but if you only use the car from time to
time you'll be fighting a dead battery more often
than not.
My quick fix to this problem was to disconnect the
wires which go to the door switches. Every thing
appears to work fine without this connection. A
"smoking gun" is that the door switches were changed
in 1991 so that there are isolated contacts feeding
this control unit instead of the 1990 version which
shares the switch with the overhead light unit..."
Hope this helps guys...
