My solution for my '82 258 c.i. Spirit GT was a simple manual toggle switch on the dash. Depending on where you drive, the fan is not necessary as long as the car is moving in summer - the "radiator" and the thermostat/water pump in the cooling system will handle the extraction of heat from the engine. It is a fairly large block, so a lot of heat is dumped directly to the air and metal around the block by radiation and convection. I found that the fan was most beneficial to cool down the engine in parking lots in summer - the only time I ever switched it on. An engine coolant temperature guage is a good and inexpensive augmentation. Power gain is probably 15 HP with the electric fan, and you give away a lot of vibration by chucking the steel windmill - really noticeable off the line. B. Nelson '82 Spirit with '85 Buick rad fan -- No virus found in this outgoing message. Checked by AVG Anti-Virus. Version: 7.0.300 / Virus Database: 265.7.0 - Release Date: 1/17/2005