So I ordered a new fan switch today 97/92 when I picked it up a couple of hours later it was a 98/93 oh well I'll try that. I have just fitted a race line water rail so I fitted the switch into the thermostat housing,got it up to temperature and the fan started on 98° brilliant. So just as a experiment I thought I would fit the same fan switch into the radiator and the fan didn't start until 101°. Later today I am going to fit my 92/87 switch into the rad to see if it comes on at 95°. The sensor for my VDO clock is at the rear of the water rail and fan switch is in the rad.