ST205 Problem

[PYATES2]

Hi there

I have a problem with my ST205, when there is no key in the engine light, lights up but when you turn the engine on the light goes off.

I've followed the drawings, for the life of me I can't find where or what's causing it. Plug C Pin 8 on the cluster, blue/silver wire has 10v permanently on it. I've traced it out an it bells out to a pink wire on the ecu? 

I've also checked the earth on the plug to ground and that's at 0.1 ohms.

Has anyone come accross this before?

Cheers Paul