Oh I see...you mean the plug that connects to the fan motor??
At present I have three wires (as above) coming out of the rad switch - the red/black is cut and goes nowhere, the red/white goes to the rad fan motor and the red/brown goes back into the loom somewhere.
So you're saying that the rad fan motor should also have three wires (because it currently only has two) - the red/white which goes back to the rad switch, a red/brown (I think) which goes back into the loom and this red/black which also goes back to the rad switch?
I haven't got the loom with me to check but I'm guessing that if I look at the fan motor plug then this should have space for 3 wires then!?
Cheers,
Chris.