I have recently purchased a 1986 IROC Z28 with a Tuned Port Injected 305 ci engine. I need to replace the radiator fan switch and I can not find it on the engine. The switch is a one wire thermo type switch with a round lug. I hope one of you can tell me where it is located. I have have looked all over the heads and intake manifold and the only one wire sensor I can find is the knock sensor down by the starter. I have a chilton manual and it does not show the location of the radiator fan switch.