No electric windows or heater blower with ign on

[ajay]

I have completed my s54 engine conversion in a pre facelift E30 the windows and blower work with any door opened but not with the ign on. Pin 15 black green is in the c101 engine plug but no cable in the socket side (from the fusebox to the c101) the blue relay (below the glove box) is live but im sure it requires a - neg feed to operate once the ign is on, iv'e checked via the search and there are a few posts but for later post face lift cars, im sure some of you guys have come across this before. Thanks in advance chaps.