The supercharger is definitely engaging when cold, the car accelerates like a scolded beast, then when its warmed up the sc fails to engage and performance drops, give it a few minutes and the sc engages again and accelerates well. I've been unable to detect any power to the ic cooling pump and so hopeful that its just that not doing its job. Somebody on MB forum said that MB used to change the fuse, relay and pump ALWAYS together....hence why I'm trying to locate the relay.

I will try changing that IAT sensor though if i get nowhere with the relay search, thanks for your reply and advice, nice to know that I can come to this site for advice,