another plug to chase up, C-2055 as that's the only other number i can find in relation to potentially the reversing lights but the loom doesn't show up any other plugs or any other wires going to it to link up with the vss loom

and there is nothing further on the location of relay S2, because it doesn't even tell the location of where relay S1 would be

i'll start on the granada diagrams tomorrow and go through them to see if they show the vss wiring, but a quick look through hasn't shown anything up so far but i'll keep at it