Topic: 67 missing a/c component

[socalgt]

It appears that some '67 factory a/c cars have a gold colored valve mounted to the right, upper firewall area, mounted with two bolts.  Some don't seem to have it.  It appears to have two nipples for water hoses, one left, one right and a small one on top, I assume for a vacuum line.  If the holes are there for it, should I assume it is missing?  I tried to attach a photo of it, but don't know if I attached it correctly to this post.

[67gtasanjose]

The valve in your picture looks like the one on my 11/66 San Jose built. It may be true there are some differences on a few examples from various assembly plants/dates if another valve was substituted but I believe what is pictured is what Ford engineering intended for use.

If you look around other threads of this site you should be able to find pictures of air conditioned cars with this valve in place. In the '67-'68 section, try using a keyword search of "unrestored" "vacuum" just to name a few and pull up a few of the threads.

My guess is if the holes are in the cowl panel, somebody changed yours to a different version. The holes would not be there on cars without factory installed Air Conditioning (for example)

[TLea]

All 67/68 cars with AC used that valve

[Richard P.]

All 67/68 cars with AC used that valve

+ 1

[socalgt]

Got it....heater control valve...keeps heat and cooling operating separately.

                                            Thanks....

[67gta289]

Technically the heating and cooling are not operated separately - we need the option to blend hot and cold to avoid extremes.

From the service manual, here is how the water valve operates:

A vacuum switch on the evaporator case is actuated to supply vacuum to close the water valve when the temperature lever is in the maximum cool setting and the A/C-heater, air distribution control lever is in either A/C position.

So when the temperature setting is a max cool (independent of actual temperature, independent of whether or not the AC compressor clutch is engaged), the valve closes to prevent hot coolant from circulating through the heater core.   Without it, the AC system would have to "fight" the heater core contributed heat input.

[67gtasanjose]

+1 to Johns comments, with a few adjustments (in red) for clarity


 

Technically the heating and cooling are not operated separately - we need the option to blend hot and cold to avoid extremes.

From the service manual, here is how the water valve operates:

A vacuum switch on the evaporator case is actuated to supply vacuum to close the water valve when the temperature lever is in the maximum cool setting and the A/C-heater, air distribution control lever is in either A/C position.

So when driver sets the temperature setting is a to the Max OR Fresh (independent of actual temperature, independent of whether or not the AC compressor clutch is engaged), the valve closes to prevent hot coolant from circulating through the heater core.   Without it, the AC system would have to "fight" the heater core contributed heat input.

Also, as John indicated, a driver can adjust or blend the temperature of the air coming out of the system EXCEPT when this valve is closed (in the MAX or COOL settings) Hence the name that Ford uses for factory installed AC systems "SELECTAIRE"

I believe the compressor only engages if the FAN speed is NOT off while in the COOL and MAX settings also (meant to read you get the compressor engaging anytime the fan is on in any speed while in either of those two panel settings) In the wiring circuit, there are also both an AC control switch AND the AC thermostat switch that help with the cycling of the compressor engagement, these were included in the design to assist the operator in controlling whether or not the compressor is "ON".  A proper functioning system is as nice as most modern systems with the exception of fuel economy. These piston compressors are NOT Eco-friendly, prompting many people to convert to the popular (but not Concours) SANDEN compressors.

Richard

[socalgt]

Thanks for the replies....I'll hope the previous owner removed it for some reason other  than preventing water to go into the heater core, possible due to a leak.

[67gta289]

If the heater core is bypassed, could very well be a leak.  If the valve is missing but the heater core is not bypassed, was probably a failed close valve resulting in no heat.