Hey guys, I've just recently completed my restoration and for some reason, when I switch between heat, floor, defrost, etc., nothing seems to happen, usually there's a hissing sound as it closes or opens the vent flaps... I've recently replaced the heater controls, and I did double check, all vacuum lines are intact and in great condition, any idea what could be causing this?...

 

Oh and I did look at the flap inside the cowl, looks to be open, and no matter what I do, it won't close... Thoughts on what it might be or where to start to pinpoint the problem?...

 

Alright, after some checking, I believe that I found the problem... Mounted to the firewall by the distributor is a sperical vacuum pod of sorts, I'm assuming this is where the system gets it's vacuum source, the top hose is plugged in, it runs thru the firewall I'm assuming to the heater controls, but nothing on the bottom nipple, so I'm assuming that there should be a vacuum line there, if so, where does it connect to the engine, maybe a vacuum tee behind the carb of sorts?... I currently don't have a tee there, just a plug as it has a 4 speed, I've looked and can't find a vacuum tee with just one small nipple, anyone know where I can get one?...

 

Alright, well that didn't fix the problem, got the vacuum line hooked up to the pod, but still no switching of the ventilation when switched, no hissing, notta... Any other ideas fellas?...

 

Update... Well, looks like the defrost is now working, so it will switch in between heat and defrost without issue, but still won't switch to standard blow in your face vent, the flapper inside the cowl remains open, doesn't seem to matter what I do, it just won't budge, and of course there's still no hissing as I'm used to with these old cars when switching anything... So yeap, still lost...lol

 

I hate to break into the conversation you've been having, you seem to be helping yourself somewhat alright. lol
I wasn't aware your heater controls were vacuum operated. Aren't the lever controls cable operated to the vents?

 

Ya right, it's like I have been having a conversation with myself...lol I was assuming that the cable was only switching the hot and cold, I believe that the vents/heater/defrost control is all vacuum actuated, at least that's what I've always taken from it, is that not the case?...