From ex Auto sparks 50 years...now retired 75 , Fully conversant with "Bosch K & KE " Systems, the early S1s used a silver relay as you all know...later S2s used ether "Siemans" grey relay...or "Fords pink relay" the later relay S2s is a much better relay and can be used on S1s, the terminal numbers on Early silver relay..ie..."15"..."87"..."30"..."31"..."1" are all on the Pink & Grey relays as well...so just swap over...you will note the Silver relay has 1 more terminal ...ie "50"..just tape up safe...NOT used on later relays....Just for info wiring colurs are [ "30" Red ]...["15" Black]...["87" Red/black tracer ]...["31" Brown ]... [" 1 " Green/red tracer ]. Hope of help. Pete.