Long Story, back in around 1979 I had a custom 3 core copper radiator built for my 6 cylinder Volvo 1800E. I had the radiator shop put in a bung in the lower cold side for a VW cooling fan switch to which I attached two Subaru pancake cooling fans (the only pancake type I could find back then) and stuffed it into the nose of the car. Not knowing how many amps the two fans needed, I hooked them up to a Ford starter solenoid. Anyhow, the fans wouldn't turn on until the car was boiling over so I just installed a switch to manually turn on the fans when I was in traffic.
Reading Alaskan Crankwalk's Ferrari thread, I discovered that they make a hot climate low temperature 80C(?) switch. After a couple of hours of searching on the crappy interweb, I am coming up blank. Anybody know where I can find such a thing? Thanks
Go find the old guy at NAPA and get him to pull out the big Belkamp books for you. They've got all the sensors listed with connection type, temperature ranges, threads, etc.
Rock Auto has it listed for $5.63.
https://www.rockauto.com/en/moreinfo.php?pk=488621&cc=1284948&pt=4312
If it is like my Quantum, the switch handles heavy current.
Thanks Keith and Pete. I can't really read the photo on RockAuto, but it kind of looks like 87-77 C which is probably what I already have. I'll stop up at NAPA tomorrow and see if there is anybody older than half my age. 
In reply to VolvoHeretic :
Go to Volkswagen - 1979 - Rabbit - 1.5l (not diesel) - Electrical Switch & Relay - Radiator Fan Switch. The item I deeplinked is listed as the 82C switch for hot climates, normal is 92C.
This link maaaaay work.
Thanks Pete. That makes much better sense, so 82-77 C or on at 179.6F and off at 170.6F.
Agreed with Pete's deep dive that the "low temp" version is ~80C and the regular ones are ~90C and are usually listed like that and not as specific.
