front air vents?

My 65 is very drafty, ice cold air coming from under the dash. I closed the rectangular vent, by my feet. Where else to look? Its a ton of air coming in.

This is whats behind the dash.

Unless one of the seams under the windshield is opening up the only other hole should be the heater box. Maybe around the wiper shafts? There is some sheetmetal in the nose that directs air around , possible rust through? Haven't seen that before tho.

Thanks! I'm betting loose wiper mount.

take the fan motor out and stuff a rag in there to see if thats where the air is coming from,,,,,,

Are the baffles intact inside the heater box duct?  They are only spot welded to the control levers, mine where both broken loose after 50 years of use/neglect.  I was able to repair them with pan head screws and washers to form a clamp to reattach them to the lever shaft.  (brazing would be better if you have a welder, I don't) They should also have felt seals around them so you can shut off the outside air coming through the fan with the right side lever to the off position.  The vent door on the drivers side also had a rubber seal or air will come right around it, 1/4" x 1/2" stick on weatherstrip fixes that, I needed that too....

My Brake master cylinder floor plug...the metal part is rotting away so I started messing with it and chipping away at it and has never really fit in snug like it did back its day. The other day getting on the freeway and obviously going faster all of a sudden felt like an airplane losing a door and air just blasting in. My plug was lose enough that the air just blew it out the way to the side but I hadn't noticed yet. I thought something went lose and that air was coming from under the dash. But I quickly remembered I messed with the plug and I never put the floor mat back on. I looked down by my feet and sure enough the exposed hole was there. The air was coming through the master cylinder opening. Just sharing this one, just in case its a similar situation.

I think it's in the vent system. Ill sort it out when it's not single digits out.