Is the small vacuum line the one that controls the heater control valve? If so I don't have vacuum on it when set to HTR and full warm. I'll have to play with it. The water pump side gets hot but doesn't pass thru. Plus I have the valve installed backwards which isn't helping. Thanks.
The vacuum for the entire HVAC system is stored in a container on the firewall. That container gets engine vacuum from a fitting at the back of the carburetor. If that is missing, or the storage tank is leaking, there will be no vacuum for the controls or the valve.
Thank you very much again Larry. There's my answer. I'm having a hard time figuring out the 50 year old drawings for the HVAC stuff. There's a vacuum line going to the firewall side fitting on the container from the carb, but nothing on the engine side fitting. I'll fix that. What is that line coming out of the firewall then? Was it going to that multi-vacuum fitting on the front of the intake for all the other stuff I don't have anymore?
The vacuum storage container has a thick line and a thin line. The thick line is the supply line from the back of the carburetor. The thin line is the supply line to the HVAC controls in the dash. There is also a thin line for the heater control valve. Maybe you have them reversed.
The line with the white stripe is the heater control valve line. Depending on application, the heater control valve is either open or closed with vacuum applied. Big car valves are opposite of A body applications. So, are you getting vacuum with the controls in the MAX AC position?
The A\C isn't functioning. There's underhood parts removed. I plan to get the system working and changed to R134 at some point. As far as any vacuum, I didn't get that far yet. I plan to mess around with it tomorrow. I'm not familiar at all with these old vacuum operated systems... or having a car with A\C for that matter. I don't know which control settings do what yet. The reason I want the control valve to work is because I'd like to at least to have defrost... and a little extra coolant flowing thru the heater core to keep the engine temps down. I know I can just delete the valve to make that happen. I do know the blower motor shuts off when I set it to MAX. All other speed settings work so I assume that's because the A\C system isn't complete. I did find that the door under the dash has been permanently screwed shut with a small strip of aluminum siding, and all the HVAC duct tubes are gone. Other than that, all vacuum lines are on the controls and nothing else inside is missing.
There is a high speed blower motor relay on the firewall that controls the MAX fan speed. That may be defective or missing. https://www.rockauto.com/en/catalog...trical-switch+&+relay,blower+motor+relay,3088
you may be better off with something like vintage air if you dont care about it looking a 100% original when you do add ac back. already r134 and you would have everything you need. not to mention finding the original parts that arent reproduced would cost somewhat similar maybe slightly less but not a whole lot. then you are dealing with some of the non repo stuff being 50 years old.
All true... and I've been debating going the 'new' route. But I think I can get it finished for far less than an aftermarket system. Plus I'm not dealing with 30 hours of taking the old system out and retrofitting all the new. I'm only missing the condenser and evaporator up front. Change some lines and the POA valve and get some wiring back where it should be. Fingers crossed.
