My heater controls wont give me heat or a/c. I have seen other cars of this type that have the same problem. The problem seems to occur on the cars (wagons & sedans) that have the vacumn controls and they have factory a/c! Any suggestions?
You'll probably have to find an old manual. They have heating and AC sections and are accompanied by a vacuum schematic and troubleshooting text. From there, it's just like tracing an electrical problem except you're dealing with vacuum.
The good news is that if you get under the dash, chances are you can hear the vacuum leak, and know what you're up against.
the 1st thing to check is your hot/cold water valve out in the engine compartment...its the doodad that the heater hoses will go into...and has a cable operation that opens it and closes it for warm or cold water transfer . if that fails...the vacuum pod that is closest to the right side of the car is held on with 2 -1/4" screws...undo them and pull the pod and let it hangout ...which will open the internal flap that controls airflow ...and im all typed out now
i'm having the same issue. any updates? I'm wondering if its the heater core. I can hear the fan and get very little airflow
As the Rev said, but there's a vacuum valve that connects to a Reservoir cannister (usually under the passenger fender or just inside it, that can and will rust out over time (the cannister), and that can plug the vacuum valve. If and when you make a junkyard run, look for the newer Ford/Lincoln/Mercury models with the synthethic vacuum cannisters, while you wait for an NOS replacement or make your own. Large Tomato can size. Solder up two vacuum ports (IN/OUT), and there's the NOS!
If the system loses vacumn the air will only come out the a/c vents,its actually two different systems and you can not get heat to come out the a/c vents so its time to find the vacumn leaks and there is a bunch of places to look starting at the motor and working towards the firewall and then under the dash. I had a 65 that had the same system and it was a battle to keep everything working,my 65 shop manual did not have a vacumn line diagram but found them in a 67 manual and then it was not so bad to get it working. The vacumn motor on the firewall is the one that switches it form a/c to heat and it was bad on mine so I plugged the vacumn line and tied it to where it only worked on the heat side and I had a bad vacumn can and after it was replaced I had no more problems with heat,I had to strip all vacumn parts from two different cars to keep my system going.
