TOPIC:

Hi all
I decided the next course of action was to test the fan switch, so I borrowed a multi meter set it to 2k ohms and warmed t the switch, the reading Showed the number 1, I then switched it to circuit test to double check but no buzzer sounded even when the water was boiling

The value "1" on it's own on a digital multimeter normally just means the measured reading is outside of the selected range (i.e. greater than 2K ohms)

I would expect the meter to have shown a value close to zero ohms when the sensor was placed in boiling water for a while (a few seconds at most)

The reason for selecting the 2 k ohm setting is because when the water reaches the temperature to open the switch it should read less than 0.5 ohms. That is also why I did the circuit test .

Update on the cooling fan, to carry out further tests I got a thermostat switch off a GPZ 900 part No. 27010- 1036 for £13 delivered (( about 20 USD ) fitted it and ran the bike up, at about 3/4 across the temp gauge the fan came on, been out and about in our recent hot weather and even in slow moving traffic the the replacement radiator I recently fitted is working that well the gauge rarely reaches half way .
I did find out that the GPZ has 2 switches that have different heat ratings so it’s the Thermostat one is 97 degrees C the radiator is higher.

When I got the replacement radiator I took it to a company that repairs/ recores and services rads to be told that it was full of crap and is totally useless and it needed a recore that they could arrange for £350, I decided to put some Kettle descaler in for a couple of days and see what it looked like, 2 days later it looks like a new radiator inside and works really well.