[molargoat]

Have 66 gto with Becool al rad with tranny/cooler. 16 in electric fan wired to
toggle switch on dash. Engine is stock 389 w/4BBL. Mechanical fan has been removed. The electric fan has no thermostat inline with the wiring. Can one be installed. Also should I shut off fan at highway speeds. Engine temp
does not exceed 190 degrees. Someone told me to switch off fan at cruising
speed as air will be blocked more while blades are spinning. Thanks for a reply.

[gtoformula]

You were correct in removing the mechanical fan ... it is redundant with the electric fan. Neither fan is needed at cruising speeds as the air flow into the radiator is handled with vehicle speed ... the fans don't bring anything to party. Having a manually controlled fan switch is probably a PITA for you. You can purchase electric temp controlled units from Summit or the other suppliers. They come in different temp settings or you can also purchase models that have variable temp settings so that you can adjust the temp engagement setting. They aren't very large and are usually mounted to the fan shroud or close to the radiator. One wire goes to a sensor that is mounted to the radiator like a probe ... it goes through the core and is locked into placed by a washer or speed nut. Supply wires are run to the battery or other positive/negative sources. The unit will have relay so that current is not running directly through a switch. A switch is usually not well suited to handle the current draw of the fans so a relay system is the preferred method.
I'd definitely switch to one of temp controlled units. They are safer than the switch and are also much more convenient as they will allow the fans to engage only when necessary.

[Philcol]

You can also buy an electric fan switch that has a probe the screws in the water jacket or water crossover. They are preset to come on. I have a 190 degree in mine so I don't forget the turn the fans on.

Phil