Mark you could probably turn that fan on with an Autometer pro light sender in the intake....run the fan ground through it. I dont like those probes that sandwich in between the hose and the rad.....always a chance of something happening. Im not sure what temperatures they sell them in but im sure that will be the cheapest route without a wiring kit and a probe. I just ordered a painless (painfull
) fan thermostat relay kit for a customer and at almost 100 dollars it isnt that affordable but I needed a trouble free kit with no BS.