I gutted my car earlier this spring to paint the engine bay and get the car ready for it's LS7/570, Tremec T56 Magnum F swap. I painted the engine bay this past Saturday and now I'm trying to figure out where I'm going to mount my Holley Dominator ECU. To do this, I had to re-install the big HVAC box under the dash. When I put the box into place, it looked like something was missing to the upper right under the passenger side of the dash. Look at the picture below.




In the upper part of the picture where the blue tape says, "orange," is there supposed to be something there? I know there is some more insulation that goes against the firewall but is there another piece that goes over the "orange" labeled vent?

I'm starting to think not because I found this picture on my computer of when I was disassembling the car last spring:


If you look past the black connector that I am not holding, you can see the same vent. There is nothing covering it.


Please let me know. I have parts scattered in several areas at my house. It's possible that I misplaced parts.

 

"orange" may refer to the color hose that was attached to the recirc servo from the control head.

 

I should've clarified that I wrote "orange" on the blue tape so I know which HVAC hose connects to this servo. This was a 100% running, driving, low mileage car that I tore down for my swap. All the HVAC system worked just fine before my teardown. Well, the AC was only barely cold but I'll completely redo the AC system.

This servo opens and closes the white colored door/valve. This seems to let a bunch of air into the car without the air going to the AC ducting system. That's why I'm wondering if I misplaced something and need to look for it.

 

I have my full HVAC system disassembled at home. When I get home I'll snap pictures of what I have.

 

Thank you!

 

The heater case presses against it. Sealed with foam strips.

 

Is it the first picture with the black, rubber looking seal? I don't remember seeing that on my car. I certainly didn't see it today when I was looking for missing parts. Maybe my car was missing that part when I bought it in February of this year.

The second picture shows a grey, open cell foam seal. I have the same on my HVAC box and that foam presses against the venting under the dash right in front of the center console.

 

Correct, almost like a gasket to the firewall

 

ratfink, thank you for those additional pictures. I don't think that my car had them when I bought it. In my second picture in my original post, it's clear to see that your part is not in my car. That picture was taken before I took everything apart because you can see the black HVAC box still in place in the upper left corner of the picture.

That part almost looks like some type of air baffle. It doesn't connect to the HVAC box at all. My HVAC box has no opening that would connect to it. I'd like to get my hands on one of those baffle/covers but I don't know what they do or if they're even necessary.

BTW, my car was also missing the underdash "cover" to hide wiring, etc. on the passenger side and I'm assuming there was one on the driver's side as well. My car is missing both.

 

This part came off my 92. When I remove the HVAC from the 88 I'll let you know if it looks the same.

 

OK. Maybe you could just look up under the dash of the 1988 and see if It looks like what came off of your 1992.

Whatever it is or does, I guess I'm going to have to try to find one. I wouldn't mind finding the under dash covers as well.

 

ratfink, I looked at your pictures again in post #8. In your second picture, I can tell that the piece that you're holding is the exact same piece that is on my car as seen in my first picture in post #1. Mine has the vacuum servo (blue tape) and yours does not. I'm assuming the first picture in post #8 is the other side of the same thing.

 

That's correct. I removed the servos to wash all the HVAC components in my dishwasher. One of the few upsides to being a bachelor

 

I was looking through my 1987 Camaro shop manual and I found this:



According to the above drawing, the item that ratfink is holding in post #8 (also what I have in picture 1, post #1) is what controls whether or not cabin air is recirculated through the car. This is shown in the far right of the drawing. In other words, max AC. It can also let outside air in via normal AC and vent. Maybe some other functions as well.

I couldn't see how it was connected to the HVAC box but the drawing makes it clear. It's connected by the engine bay, AC evaporator box.

It still seems like there should be a cover/baffle/filter over this thing. Obviously, I don't have it but I'm not sure that it's even necessary.

 

Oh! I misunderstood what you have been asking this entire time!

Yes, that's the recirc door. The only screen that it has is the screened opening over the wiper transmission, which is why it's critical that it's sealed to the plastic. The default position is open, so that in the event of loss of vacuum, the cabin is vented.

I read WAY too deep into your question. My apologies.

 

Ok. So looking at my first picture in post#1, that’s how it’s supposed to be, right? No cover of any sort over that valve.

My screen is intact over the windshield wiper mechanisms.

 

With everything fully reassembled, that should not be visible. The heater case should go over it under the dash. Do you have a heater xore installed?

 

No. The heater case does not go over it. Here is a picture I just took showing my heater case in place and there is no opening in the case to connect to the valve.




If you look at the shop manual drawing, you'll see that the only way that valve is connected to the heater case is via the engine side, AC evaporator box.