> I also had the radiator shop put a "bung" in so I could use a modern
> "screw into the radiator" thermostatic switch to control the
> operation of the electric fan. I still need to find a switch that
> closes the circuit when it reaches temp - the first on opened the
> circuit. :-)
John, I would strongly suggest that you use a relay between the switch and
the electric fan.
If you do, then the "normally closed" switch will not only work but provide
an extra margin of safety. All you need to do is find a relay that has both
NO and NC contacts, and use the NC contacts to control the fan. Thus when
the switch is cold, it will pull in the relay, which will keep the fan from
running. If the switch contacts go bad, or the wire to the switch gets
knocked off, the fan will run all the time, which will both tell you
something is wrong and keep your engine from overheating until you fix the
problem.
Don't recall the P/N offhand, but I got 30 amp relays with both NC and NO
contacts for under $5 from JC Whatnot. ISTR adding a socket and harness for
them brought the price up to about $8/each.
Randall
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