Seat belt pre tensioner help required

[BusyBuilder]

I have a Hymer B544 Fiat based 2011 model. The AGUTI driver/passenger seats have pretensioners fitted to the seat belt stalk (left side of driver seat).

Our Pointer dog chewed the black/red part of this and although it still works I've found a replacement part which is actually off a Ford Focus Mk2. They are identical except two wires are different colours. There are 4 wires in total red &black (same as Fiat/Hymer) and blue & yellow (Fiat/Hymer are grey & green).

Can anyone help with the colour differences (grey/green to blue/yellow) and connections between Fiat/Hymer and Ford ?

I'll post some pictures later

Thanks

 

[BusyBuilder]

Hymer/Fiat fitted part on Aguti seat (photo 1).
Yellow connector (photo 2) is Fiat part that I need to reconnect under the seat.
Two connectors are Ford (photo 3) and photo 4 is Ford seat belt pretensioner.
Both seat belt pretensioners have identical part numbers and other ID marks and are a direct replacement on the Aguti seat, it's just the 2 coloured wires that are different.