The multi-connector has pins/terminals appropriate to what systems the car was built with. My 2002 was not pre-wired for seat motors or heat, and (from several threads over the years on UKSaabs), some cars didn’t have these options but did have the wiring, some had seat heat wiring including the sockets behind the seat heat switch positions, and some had seat motor wiring.
I added a set of 2000 motorised seats to my 2002, got the wiring diagram, and added every wire that was missing. This included adding new pins in the multi-connectors, and the corresponding female terminals. There was, from memory, a wire running from one seat to the other, as there was a control relay under the passenger seat to energise the whole system.
There was also a connection to the iBus to enable the aural tone when using the memory position setting.
Others have got both seats working with much simpler provision of simply a +ve to each seat, but I wanted full original functionality. E.g live motors when the door is opened, with the key not in etc.
I’m no electrician! The WIS diagrams give the pin position numbers for all the connectors. I butchered some spare connectors to obtain extra pins/terminals.
Doug