Uprated Radiator fan switch for All Sierras.
This switch will usually switch on your fans at around 90 Deg C and Off again at around 87Deg C

It works the best and closest to those temperatures in an uprated alloy radiator, but it is a good upgrade for normal radiators too in my experience, working around 93/90 in std radiators.

this was taken from stu's ad on ebay for his uprated switch.