Hi Andre, welcome to the forum.
IIRC, the '93/'94 cars can be a bit awkward in that Volvo seemed to be trying different solutions before settling on a standard one - so many parts are unique to those years. It is further confounded by Volvo using different part numbers for the same part (!)
As Rudi suggested, give FRF at Swansea a call - they are very helpful when you can get hold of them - but be prepared to be very patient as they are very very busy. I'd suggest that you have you reg number and VIN to hand, just in case they can't recall the VIN from your reg - the VIN may be needed for part number changeover points.
NB I have heard of the resistor pack being referred to as a powerstage - its a US terminology not frequently used over here, hence it being lost in translation
Good luck!