Rover 75 M47 2 speed fans

[Sville]

I apologise if this has already been covered, but the fan on my car is not working. I have removed it from the car in the hope of finding the problem. It has a gold resister showing continuity as do all the wires from the pugs to the control box apart from the thin blue one which has intermittent continuity.I am hoping that is the problem. The fan itself runs if connected directly to 12v. I am no electrician and would struggle with any wiring diagrams, but I understand the thin wires control the relays. I would like to know what colour wire controls what.

Many thanks in advance.