Adjustable Temp Switch Wiring Q's

[MercuryMarc]

I picked up new adjustable thermostat fan switch with a submersible probe at the Good-Guys swap meet. Unfortunately the wiring instructions are not very clear (to me anyway). The switch has a long wire attaching to a 2 inch temp sensing probe, an adjustable knob, and three terminals on the bottom. The terminals are labeled 1, 2, and C. The instructions say to attach 1 to the fan motor, 2 to the 12 volt positive source (with a fuse), and C to the "compressor coil." I understand the 1 and 2 but not the C to the compressor coil. The unit itself looks like a relay but with only 3 terminals (my other ones have had 4 terminals). I can't tell the manufacturer but the back says "Made in Korea" and has a relay diagram on it. Any help would be greatly appreciated.
Thanks-
Marc in SF
http://mercurycomet.net

 

[80broncoman]

I belive they are refering to the clutch or coil on the a/c compresser if your car has a/c. The switch will last a whole lot longer if you use a relay.
Some fans can pull alot of juice.
Jim