Running Fan

[76okievette]

Is it normal for the interior fan, heater/AC fan, to run on a 1976 with just the key turned on? Basically the fan runs all the time the key is on even if the motor is not running or the fan switch is not turned on.

[Jack]

It is normal for other years of same era ...same for most if not all GM cars of same era ... probably normal for your year (76) but I can't confirm.

FYI ... GM's "fan always on" configuration was referred to as "Astro Ventilation" ... was a marketing plus ... also sometimes referred to as "flow-through ventilation." My 71 has "Astro Ventilation" etched into both door glasses ... I dunno what year they quit with the etching but the ventilation system continued in production long after they quit etching.
JACK

[Stallion]

What's the idea/advantage behind this?

[Jack]

Originally Posted by Stallion

What's the idea/advantage behind this?

Quite simply ... it continually exchanges the atmosphere in the cabin. This is a good thing because ... without it ... unpleasant odors, humidity & even worse... exhaust leaks (CO) can build up when all windows up (in a tight car).

BTW ... such systems include small vents-ducts to facilitate flow ... sometimes in door jambs.
JACK

[brusso]

I beleive thats why the astro vents are there behind the rear window, for those years. I think that I read somewere that they function as vents only on non a/c equipped vettes. My 75 has/had (thats a whole other story) air conditioning so mine are just for decoration.