I was replacing my aux. fan relay and noticed this under the left hand fuse/relay bracket.
Should it be plugged into something or does it just suck air for some purpose?
...Jimmy

 

That is air intake vent for distributor. Do not plug it and you should check it and it's pair are both intact.

 

That is the air filter to goes to your distributor cap.

There are two hoses to the cap. One is a vacuum hose and the other is a vent with a filter on the end. Air is drawn into the filter from the vacuum.

One end of the filter has a hose that connects to the distributor cap. The other end of the filter has no connection. The filter and hose are usually tie-wrapped to the underside of the firewall to fender bracing strut.

Mark

 

You said "it's pair". Where is the second one located?
Thanks...Jimmy

 

Varies slightly according to ignition type (marelli verses lucas) but both hoses run from distributor with one connecting to T connector between extra air valve and LH air cleaner backing plate and the other is the one you have in pic.