I don't want to tread on toes, but I think there are a few incorrect statements here. This is my understanding of the various wing mirror variants. I've grabbed some photos from ebay here and there to help augment the words:
Wiring
There are up to 9 wires in a door mirror. The colour codes are:
Blue, yellow and red wires - electric mirror adjustment. As far as I know, all UK Multiplas had electric mirror adjustment, so you'll find these wires on every mirror.
Red/purple and brown/black striped wires - folding mirror motor
Black and white wires - Power for heated mirror element. Only the larger (top) mirror glass is heated, not the little lower one.
Purple wires x2 - Outside temperature sensor. Only present on cars with climate control (
not plain aircon) and only fitted on the OS (driver's side) mirror. The tell-tale for their presence is the little black nipple sticking out of the outer rim of the mirror housing.
Mirror type 'basic'
NS (passenger side, left hand) mirror: Part number 735264232. Just the blue, yellow and red wires, in a 7 pin plug. As shown in the two photos.
OS (driver's side, right hand) mirror: Part number 735266577. Same wiring and plug as above. No photo