HV Ducting

[84StangSVT]

Yes you read that right! Since I don't have A/C, I can't call it HVAC ducting. That's just wrong in my line of work.

Anyways......

I'm a bit bamboozled by the system on the non-ac cars......or maybe I should say my car. I understand the operation of the cowl fresh air ducting, the floor ducting but the dash vent operation has me baffled. How exactly do the vents hook up to the main system and how does the air flow through them?

To me, on my car, it appears that when the cowl air vents are closed and the heater/fan are on, it pulls the supply air for the system in through the cowl vent tube on the P/S. From there it either distributes it to the floor ducts in the center of the car or through the defrost vent. I do not see anywhere that connects to the supply side of the heater box to the vents. The cowl air tubes have foam on them like they connect from the tube to the vents but nothing else.

This seriously has me going stir crazy. Am I missing parts other than the extension tubes or do the dash vents only work with the cowl vents when they are open?

[homer302]

Sorry, It doesn't look like I have pictures of the back side where they connect. Yes, my car is an AC car so the vent itself is likely different but the placement and function should be the same. You can see the rather large black plastic piece running from the vents and behind the instrument cluster. I am also aware the Non AC cars do not have the vent in the center. Just trying to help.

[84StangSVT]

Sorry, It doesn't look like I have pictures of the back side where they connect. Yes, my car is an AC car so the vent itself is likely different but the placement and function should be the same. You can see the rather large black plastic piece running from the vents and behind the instrument cluster. I am also aware the Non AC cars do not have the vent in the center. Just trying to help.

I had the same set up in my vert as it was an a/c car and there was not only the defrost duct tied into the dash, it had another duct running in there that connected the vents. That is my question I guess......do the non-a/c cars have a duct that connects the vents, minus center vent, in the dash also?

[84StangSVT]

The pics above show that the defrost vent appears to sit directly on the only outlet to the heater box, minus the floor vents.
This is really what has me messed up. I don't see anywhere a duct could hook up to the vents and be functional for heat on the non-a/c system.

The A/C dash I had was way different than this setup as seen below. With all the ducting and vacuum operated doors, I understand how it works.

[erratic50]

Swap your heater core and put in a restricter while you are there

[homer302]

Swap your heater core and put in a restricter while you are there

It's a non AC car. It takes 5 minutes to put a heater core in it with the dash fully intact.

[84StangSVT]

I'm about ready to come to the assumption that this car flat out doesn't have any heat connections to the vents. I test fit everything and the defrost duct in fact sits on the blower box, so it doesn't appear that there are any missing pieces there. The heater control has heat/defrost mode and nothing in between. It is cable operated with 2 cables. It appears one for the blend door and one for the flow direction. The flow direction appears to be either to the floor or to the defrost. Judging by the foam tape on the cowl ducts and dash, the vents on each side are connected straight to the cowl ducts via tubes.

My consensus is that Ford never planned to have heat to come out of the dash vents of this car, because people in the 80's were tough and didn't need to warm their hands in the winter.

[84StangSVT]

Swap your heater core and put in a restricter while you are there

It's a non AC car. It takes 5 minutes to put a heater core in it with the dash fully intact.

Heater core is fine. There is one good thing about having a non-ac car, pop the glovebox out and the heater core is right there.

[JACook]

I believe '85 was the first year those vents were used for anything but fresh air on non-A/C Mustangs.

[84StangSVT]

I believe '85 was the first year those vents were used for anything but fresh air on non-A/C Mustangs.

There I go! That is what I was wondering and that answered my long question. Looks like the vents are utilized for fresh air only on this car. Thanks Jeff.