sensor/switch on '82 Caddy diesel

[Blue Haze]

I see a small "sensor"  in front by radiator behind the plastic vent panels on the right side.  What is this and what does it do.  I think it is ambient air sensor but not sure.  This is on a '82 caddy diesel w/air. 

[ORCoaster]

That sensor is for determining when the Caddy gets up to 100 mph.  All sorts of horns blow and the lights flash in sync with the song Staying Alive from the Disco era.   Trust me. 

[damac]

Mine doesn't have any sensors over there outside of the fan temp screwed into the radiator.  So I have to assume the other persons reply or something to do with air conditioning?  Never had an ac chasis myself