Door mirror issue (not the usual reverse question ;) )

Hi, I'm looking for some help with diagnosing a fault I have with my electric folding door mirrors on my 2004 33oci clubsport with electric memory seats and mirrors. The problems is as follows:

1. Both mirrors fail to move when using the adjustment switch.
2. Only the passenger door mirror operates when the car is put into reverse
(regardless of where the switch is positioned)
3. Only the passenger door mirror folds when the lock button is held down on
the key.
4. Only the passenger door mirror 'defrosts' when iced.

So far I know it's not the fuses, mirror adjust switch or a disconnected cable in the driver's door, or a loose connector from where the interface cable from the door connector to each of the components within the door.

The electric windows work fine, so I know some power is getting through the connector but I don't want to assume that means the mirror assembly/switch is getting the correct power. Can anybody advise if they take power from the same source or not?

I know that the airbag power/monitoring system seems to be ok as I now have the airbag light on after my tests so far

I'd be grateful if someone could shed some light on where the control module for the mirrors is hiding or any other possible cause I've not yet considered.

Many thanks