thermal switch for electric fans January 15, 2007, 01:29:27 PM http://www.tod.com/productdetail.asp?ProductID=89good thermal switch resource for those considering an electric fan.this would screw into the engine or radiator ,,or elsewhere as you would find results to be best reguarding when the fan kicks on as it relates to temperature.parts requiredyour choice electric fanhigh wattage/amperage automobile relay from a junk yard, or no relay, just a pos wire to fanwiringthermal switch installed on the ground side of the fan. Quote Selected