A 5 inch round hole in my firewall

[nicolosisa]

There's a 5 inch round hole in the fire wall of my '54 Manhattan, high up under the dash and above, and to the left of, the driver's left foot.
I have remnants of the 5" wire-supported black flexible air vent tubing, still attached under the front of the front fender, so I know "where the air is coming from",
 but inside the passenger compartment, there is "only the hole", so where is this vent tubing "supposed to terminate"?? I think something is missing.

[G.B. (All Vinyl Dragon)]

Please Send Pictures So We could Help.

[nicolosisa]

It took me a while to figure out how to get a photo off of my phone and into my computer.
Here is a view from the inside of the passenger compartment.
Please ignore the steel screen mesh, it is something that I put on the "under-the-hood side" to keep small animals out of the car.

[joefrazer]

There once was a flexible air vent host that ran from the hole in the firewall to a metal vent tube that rides above the wheel. Attached is a picture of the hose routing.

[nicolosisa]

Thanks Joe,
I understand the "under-the-hood" part.
I have even found a source for a black neoprene flexible tubing that I consider an acceptable substitute for the factory-original black "tar paper" version.
But what I can't figure out is the part "inside the passenger compartment". 
That flex tubing didn't just "hang there" above the driver's foot, did it?
Wasn't it "attached to something" inside the vehicle?

[joefrazer]

On the engine compartment side, there should be a flange that sticks out about an inch or so. The flex hose attaches to it and is held in place by a large wire style clamp. It sounds like the flange might missing on your car.

Beyond the air deflector in place now, nothing else mounts under the dash for the vent.

[nicolosisa]

Thanks Joe,  There is a firewall flange in the engine compartment.
I haven't actually purchased the black neoprene jacketed flex hose yet, so I didn't realize it will be large enough to attach to the outside of the flange.
I thought that the flex hose was supposed to pass "through" the flanged hole, because that is how I found the old  factory original flex hose ... which was little more than a copper-wire "slinky" that I found hanging down into the passenger compartment and tangled around the brake pedal. 

It hadn't occurred to me that the hose was intended to mount to the "outside" of the flange... I thought it was supposed to pass "through the flange... I now know I was mistaken.

[Terry T]

you need a shop manual and parts list to work on any car, especially vintage ones!