cooling fan
Painless makes a thermostat switch that threads into the stock head. Unfortunately they only sell it as a kit with a relay and wire. I have yet to find a source of metric thread temp switches, so if you want to go that way you need to turn down a 3/8 NPT one and rethread to fit.
Another option is splicing a fitting into a hose to fit a standard 3/8 or 1/2 thread switch.
I have an adjustable fan switch that works off a probe in the radiator fins. Think it was $40 from Jegs. Generally not the best solution but a bit of plumbers dope on the probe to shield it from the wind has it working fine.


