I have a 1978 Ford Granada with a 250 inline 6 engine with factory a/c. Last Thursday I turned on the heater but there was no heat. The water valve is plastic with a hose nipple. I connected a vacuum gauge and found that there is no vacuum to actuate the valve. Today I connected a vacuum to the valve but I still don't have heat. I just want to know if the problem can be the heater core or the heater temperature adjust before I take out the water valve.
By moving the lever to "heat" how is the vacuum connected to the valve? Is it mechanical or electrical?
The a/c cools but if I turn the lever to "hot" there is no heat.
Any help would be appreciated.