Old School: Fan relay and switch from ATR?

[Ken Cunningham]

My car has some mods from the first owner, so this one may date from the '80s. The high speed fan relay has been replaced with one that wires into an odd little switch mounted in front of the radiator. The switch is a quarter-sized disk that appears to close the circuit when the air pushes it inward (lie at speed).

The part may be from ATR, but I never saw any listing for it anywhere.

Does anybody have any idea what this is supposed to do for me? Is it worth keeping?

TIA,

 

[83ttypecooled]

Hi,
I think that is an air activated thermo switch. That's what it sounds like, anyway. If I'm right, this is not a really great setup, because they are prone to balking when it's time to turn on the fan,and then not shutting off when cool down has occurred. You need a system that senses coolant temp directly,and acts on that!