I know some comes from the cowl area but where else? I have had problems with mice getting into my heater and I can't figure out where they are getting in. Does the heater open up to the fenders also?

Thanks

 

There is a rectangular hole directly above the glove box area to the cowl area. This hole brings in outside air. Unless you have a bad EM harness grommet, this hole is the way in for them.

Later

 

I've had my interior stripped and I wanted to ask the same question.

So where does fresh air from the engine bay enter the cabin?

 

I would imagine from the other side of the heater core

 

If the heat is on. Fresh air doesn't go through the heater core, that is why it is fresh and not heated.. Doh!

 

It doesn't. Engine-bay air is kept isolated from the cabin intake to prevent exhaust fumes, excessive heat, etc., from entering the cabin. The cabin air enters from the cowl area.

 

do fd's have a cabin filter like newer cars? i noticed sometimes the fresh air is not so fresh. hehe

 

Sorry but where exactly is the cowl area?

 

Underneath the windshield. To the rear of the hood. See the little intakes?

 

The black plastic piece that sits where Baja described is the cowl.

 

So it only comes from the cowl? Can anyone verify there is not another source?

 

This is where ALL cars fresh air comes from. On the RX-7, page 4-46 of your owner's manual tells you this. This is why it is important to remove snow from this area in the winter, as sucking air thru that snowpack dramatically increases the humidity factor.

Chevrolet basically started this whole trend with their 'Astro Ventilation' in the mid '60s.

Want to test this? Get a punk or a cigarette or something that smokes and suspend it above this vent area and have someone slam a door or the rear hatch.
The resulting pressure should visibly move the smoke.

 

Owners manual, doh, didn't even think to look there. I looked everywhere in my service manual and it said nothing.