MoparDan, basically all that has been said is true. That is a vacuum motor that allows hot air entry from the exhaust manifold heater. It allow for better cold weather drivability for those colder areas (up North).
Sense you live in an area where freezing cold weather is not an issue, you can disconnect that entire circuit (put a rubber plug on the carburetor nipple). The black (or silver) corrugated hose (2 inch / 5 cm diameter) can be removed. By default, the vacuum motor only opens when it is cold, so being disconnected will not affect anything – where you are at (in sunny Florida).
Up North, it is a “must have” item.
Where I live at, Oklahoma City, OK, we do get both extremes. Last February, our average temperature was below freezing (I think the avg was 29’ F / -2’ C). In August, it can get well above 110’ F (43’ C). Yesterday, we had 80 MPH (130 kph) winds to tend to. In about 2 months, it will be officially tornado season here.
To be honest, I don’t see a lot of those vacuum motors fail. I might even have a spare in my garage – if a person really wanted to replace it. Pretty much all of Chryslers air cleaner vacuum motors will work for a replacement (if it looks similar – then it might fit and work fine) – but there are a couple of differences over the years.
There is a temperature switch that turns on that vacuum motor, that is located inside of the air cleaner. The hose from carburetor goes to the temp switch first, then goes to the vacuum motor on air cleaner.
On an unrelated note: there are different temperature ratings for the switch, and different paint stripes indicate the temp switches on at. I think Chrysler used about 5 different temp ratings on those switches (but not sure why).
Blue / Red for this one.
Dual snorkel air cleaners use a similar vacuum motor for other side (second snorkel) but it only opens when engine vacuum is low – to reduce engine noise (open only during WOT (Wide Open Throttle)).
The greet arrow (temp door motor) is the same as the second door motor (purple arrow). The second door stays closed unless extra air is needed.
Some mid/late ‘80’s 4-bbl M’s have a second vacuum motor on the side of air cleaner (black arrow, below). That motor closes off the snorkel when car is turned off, to keep fuel vapor inside air cleaner – to comply with fuel vapor emissions (on 4-bbl cars). I’m not sure why that wouldn’t also apply to 2-bbl cars – but I’ll avoid going down that road.
For giggles, I found this picture online. He found the reason for poor performance (Jeep).
BudW