I have finally gotten most of my systems functioning properly now; brakes, suspension, Alternator, engine cooling, Fuel tanks, Widow seals and the one I'm most proud of fixing, my analog clock and listening to its little solenoid kick the winding spring every two minutes!


I'm now wanting to tackle the AC system. first question is; did the series 1 have high and low pressure switches originally? Looking at what I have I don't see any. I know my system is evacuated and the compressor clutch will engage. I've started to research but still don't pretend to understand AC systems very well.


And this my be a controversial topic but I am currently considering trying propane initially.


I have not replaced any components yet. I thought Id try to charge it and see what happens first.


Suggestions appreciated.

 

No high or low pressure switches on my 71 (York compressor) or 73 (GM A6 like yours). The system is as simple as you can get. The Ranco thermostat switch (left of radio) senses evaporator temperature and operates the compressor clutch directly. The temperature at which the switch engages is set by the knob--you can hear it click on just rotated to the right from off at RT, it clicks on at lowest temp (just above freezing) when rotated fully right.

A microswitch is driven by a cam on Ranco switch shaft and closes when the Ranco is advanced from "off" at full CCW. This turns on the blower fan regardless of whether it's switched on or not by the fascia switch. On early S1's the microswitch duplicates the "low" position of the fascia switch. On later S1's, it provides a third speed, lower than "low" on the fascia switch.

The evaporator is on the small side. You can fit a center vent so that air comes out there (heat or AC) in addition to the two vents at left/right of fascia (see Archives for "center vent.")

 

Key to good AC performance is replacing the condenser with as large a one you can fit of modern cross flow design. Make sure the hoses are correct for R134 (the best stuff to use for easy of availability and understanding) and the expansion valve is working and correct for R134 fluid (stock ones need to be adjusted with the screw to allow the correct amount). I have a Trinary switch mounted that turns on the dual Ford fans when the AC is used, plus a trans cooler. The front of the radiator is sealed up to force the incoming air through the condenser and radiator with AC foam.

Fans can be replaced with GM fans for more air flow (that makes it feel cooler) and the extra air flow from the new center vent(s) will help in the comfort. The dual vents get their air from the bottom of the evaporator for one vent and the other from one the rear tubes that go through the center console to the rear passengers.

I use a Sanden compressor and have all the mods that Robert mentions above and more... get 39-40F air temps in the side vents and cooler temps in the two center vents. Part numbers and photos are available...

 

Thanks for responses guys,


Do either of you know oil/ gas capacities for this setup?

 

My local AC guy uses his machine to evacuate and then charge the system... never bothered to ask him... I do all the rest of the work but leave the final charging up to him.