GinnyH

Where is the thermo switch that hooks to the electric fan - what color wire is it?

SH-60B

Radiator fan? Factory is a clutch fan, if you have electric it's aftermarket.

Wuttin

On the passenger side of the block near the firewall (see view a in the first pic and view d in the second). I believe it is a blue wire. May be challenging to get to if you have the heat riser and shielding in place.

jb78L-82

79 L-82's had a factory mechanical fan clutch AND a small electric cooling fan inside of the fan shroud at the bottom of the radiator. I believe that is what is being asked. Only the 79 L-82's had the auxillary cooling fan as well as the mechnical fan clutch . My 78 L-82 ran hot as hell when totally stock (225 was normal and as high as 235-240) and GM must have had to do something to address the high temperatures for the 79 model year. My 78 L-82 4 speed runs about 170-175 around town and 180 on the highway but i have a dewitts radiator, stewart high flow water pump, no emissions control at all, and true 2.5 inch duals with shorty headers-the temperature dropped from all the changes by 50 degrees! I have heard that the late 70's smog heads are prone to cracking which I am not surprised by since the water temperature ran so high from the factory!

C3 4ME

The switch is in the passenger side cylinder head btwn 6 and 8 cylinder. My wiring is not connected to the switch as it's pretty worn, but I know the fan works because I've jumped it and it turned on. I've read here that it's set to come on at 238 degrees. I wonder why it's set so high?

jb78L-82

Please see my comments above^ about the temperatures that the 78/79 L-82's ran-very very high. The reason was for emissions with the L-82 and it's cam-the intake and exhaust valves have tons of overlap at idle which is a nightmare when trying to get an idling engine to pass emissions which is how it was done back then, idle not running at 2,000 RPM's. The 78/79 L-82 also has the AIR Pump which the L-48 does not. These engines were completely chocked up and run hot to pass the emissions test. My original L-82 with no emissions and 2.5 true duals, shorty headers and free flowing mufflers is a different car from when it was completely stock. It's shocking!