1999 735i trunk lid opening mechanism

Hello all,

if any body has any spare time, any help would be appreciated in
telling me how to fix the opening mechanism on my trunk lid.

The hydraulic system is only working intermittently. When it does work,
it will sometimes only open the boot lid partially before stopping. The
red 'push to close' button on the lid is also not illuminating at the
same time that the hydraulic system doesn't work. It seems to work more
often when the car has been running for awhile than when it has not
been running ( but this may just be coincidence). The locking servo
works fine (seems to be a separate circuit). I do not know where the
electronic controller or hydraulic motor/reservoir is installed, or
where the fuse is.

These are all the clues that I have. If somebody could tell me how to
test the motor from the control box I would know where to start trouble
shooting.

I would like to put my wife inside the trunk to help me trouble shoot
but am afraid that it may start working again!

Many thanks in advance.