My '66 Newport factory a/c car is as the picture, on the firewall behind the rh exhaust manifold area, same as my 67 Newport, also. Probably the same for '65-'68 factory a/c cars. My '70 Monaco has a vacuum operated valve near the rh fender brace area, as the '69 picture generally indicates. The originals had a big vacuum area on top with the hoses going through a redish lower area.
When I replaced it with one of the smaller reservoir models, at certain vacuum levels the vacuum control in the dash would vibrate as long as the particular vac level was happening. A slight move to more or less heat normally stopped the sound. The smaller vacuum area of the aftermarket valve was apparently the culprit as the larger one had enough damping area to prevent the resonance.
With ANYTHING with rubber seals, always seek out NEW rather than NOS, for the best longevity. The '55 Chevy used a similar valve as the '65-'68 Chryslers did, seems like. The capillary tube was supposed to be "an automatic adjustment" so you wouldn't need to keep moving the lever for "more" or "less" heat for a given valve position, as I understand it.
The '72 Chrysler a/c cars (not AutoTemp) use a cable to activate their water valve. On the rh fender skirt. The AutoTemp control was also used on some '70s Mercedes cars, so they are still around, too (at least about 10 years ago). Looks just like the Chrysler part, too!
On the '72 cars, possibly from '69-'73, the a/c compressor is set-up to run when the control button is "OFF". There is also a very low fan speed. This is supposed to keep fog off of the windshield or something like that. Not sure of its effectiveness.
As you move the heat lever to the right, you can feel and hear a slight "click", that's the compressor switch going to "off". The cable is a two-piece cable, too!
With the lower compression and power of the '72 engines, having the a/c compressor run all of the time was an added drain on performance and fuel economy! Many police depts. and such toggle-switched the a/c compressor so they could turn it off "in pursuit". You can achieve the same thing (at least on the '72 Chryslers) by moving the "HEAT" lever to just past the click, then manually readjust the heater water valve to "OFF" on the cable position. The level will show about 1/2 heat, but the valve is closed. Looks kind of strange, but works. Still enough heater power for moderately-cold weather. The cable adjustment is a "slip fit", so if somebody pushed the "HEAT" lever back to the "cold" position, the cable would slip in the fitting, not hurting anything, except putting things back like they were (compressor running all of the time when "OFF").
ALSO, the heater floor output is biased toward the driver's side, with less to the passenger side. You can fix this with a piece of masking tape! Just block off 1/2 of the output nozzle on the lh side and the blocked air will then go to the rh side . . . makes the output pretty even that way! Kept my mother happy and not complaining about being too cold on her side of the car!
CBODY67