Derale makes an inline thermostat that turns the fan on at 180 degrees and off at 170. Summit had it listed, but was out of stock, ended up ordering from Doug Herbert. I like ol' Dougzilla anyway, glad to give him the business. Ordered a 7" Derale fan too. Derale Part #s 13021 and 16507

Total cost was about a C-note

thanks for the input guys

Pat