Thermostat switch wiring

[Nbettley 4]

Hi Guys,

 

Following refit of an mi16 engine  i am struggling to get the fan to kick in when it gets up to temperature, I have let it go ab bit above operating temperature on the gauge but then I chicken out and switch it off as I don't want it to boil over.  Firstly does anyone know at what point the low speed and high speed fan should kick in? Secondly does any one have a wiring diagram which shows the wiring from the 3 pin thermostat switch to the shunt box and resistor?

 

[Anthony 1,000]

Temperature wise it'll depend which thermoswitch you have installed in the radiator, typically distinguishable by a coloured band around it.

 

The standard red banded GTi switch switches the slow speed fan on at 97 degrees and the high speed fan on at 102 degrees from memory - that's a little before 2/3 and around 3/4 on the gauge respectively.

 

If you pop the connector off the thermoswitch and use a piece of wire to short pairs of the terminals, you can check that the fan works on both slow and high speed - if the slow speed resistor isn't working, then yes, the gauge can get disconcertingly high before the fan switches on.

 

[petert 554]

It’s also important that the thermostat temperature matches the radiator switch temperature. For example, if you have an 82 fan switch with a 92 thermostat, the fans will never turn off. I’ve found that in Oz, 92 and 92 is the best compromise.