Re: AC in1953

Posted by HH56 On 2010/7/6 8:41:34

There are a few photos of a 54 in the photo archive but I have some from a parts car I'll try to find unless someone beats me to it. Adding the trunk unit is a job and unless you have a complete parts car, there will be lots of fabrication. Most of the components are not available so if anything needs repairing or is missing or totally not repairable, there would be your first issue.

The compressor is constant on unless the belts are removed so always moving refrigerant. Only thing the on/off switches do is control blowers and close a solenoid valve (very important piece and NLA) It uses a method called hot gas bypass for temp control. There is a heated glass thermostat in the unit which controls the solenoid valve. When cooling is called for, it closes the valve allowing the refrigerant to circulate to the evaporator and when not cooling, opens and refrigerant short circuits and essentially loops in and out of compressor. The actual changing or lowering of temp is done by heating the thermostat bulb (amount controllable by operator) which in effect fools the thermostat into thinking it is warmer than it actually is. It takes a good AC person to diagnose and work on these units because a malfunctioning gas bypass valve or thermostat mimics many other problems.

Being in the trunk, you lose the effect of nice cool air blowing on your face for the immediate cool down. After the unit is on for awhile it does cool the car nicely but I would miss the face breeze. There is a slight discrepancy in the vent area so there may be two that are correct. The car I had only had flat outlets on the package shelf similar in size and shape to the fresh air vents under dash only with straight facing louvers--not the "V". I have never seen the transparent plastic vents on Packard units that were common on aftermarket and GM cars but others have. They do not appear in the parts book but some of the vendors had them new. Without them, the rear seat passenger gets the full blast on his neck and is uncomfortable in a hurry. With them, a little more of the air is shoved toward the front seat--but still not in your face.

You are right in that no one makes 6v units. Lots of people are looking for one and many have converted to 12v just for AC reason alone. Finding a 6v aftermarket hang on unit out of the junkyard might be one option and they do pop up from time to time. One of our regular posters mentioned finding one last year. The compressor clutch is the big deal. All aftermarket temp control methods today rely on the cycling clutch and no 6v clutches seem to be available. There was one supposedly on a York compressor for a VW but I have yet to find it. Finding a 6v heater blower motor is not that difficult and if a clutch could be found, with some work and maybe a pair of blower motors due to their smaller size, a modern aftermarket unit could be adapted.