Armstrong A/C Question

[Sundance]

My newly acquired 73' Argosy has the Armstrong A/C unit. The unit fan runs but the compressor does not kick in that I can hear anyway. The outside temps are low (high of 56 F today, 64 F tomorrow). If the unit is coupled with outside temps....... Is there a way to defeat this to check compressor operation?? Does the units compressor not kick in with low outside temps?? What refrigerant is used in this?? Any one know the pressures the unit should operate at?? I am ASE certified in auto A/C and have the gauges and can buy refrigerant's. Keep in mind I am on a limited budget and even though new A/C's are "only" $300 that is a bunch to this hombre. Couple that with the time and labor of putting a new unit in and I'd like to avoid this like the plaugue. Thanks for your help.

[TomW]

My '67 Armstrong A/C unit is an R-22 unit. It does not care what the outside temperature is. Although I have paperwork on what the right pressures are, when I had Johnny Mosely replace the compressor, he humored me by casually looking at my paperwork and then explained that the pressures are a function of the ambient temp, and the experience of the installer.

I kept my mouth shut until the new compressor was installed and the air conditioner was all but turning my Overlander into a meat locker. Then I asked Johnny what the pressures were. He got pretty smug when I told him he had nailed what my antique paperwork called for.

The complete tale is at my Overlander's web site.

Tom

[TomW]

Originally Posted by Sundance

... The unit fan runs but the compressor does not kick in that I can hear anyway...

I would start with a voltmeter instead of gauges. Armstrongs have a low-volt transformer which operates a relay to the compressor's input power in response to the thermostat's request for cooling.

Member DavidZ71 has posted about replacing that transformer to restore his cooling.

Tom

[Sundance]

Went out awhile ago (57 F) and I am almost positive the unit is cooling. Hearing the compressor kick in is barely audible. The fan sure isn't a problem to hear!! I'll check again later to be sure. What a great site Tom. Thanks for sharing your invaluable experiences. I wonder if my 73' does not use a big hole in the roof??? I like the idea of small holes to be sure. Old ways are often better ways.

[ticki2]

If you remove the fibre glass cover you should find a plate with all the specs for the unit , at least on my '76 it was .

[Sundance]

The shroud was an easy removal...... one piece at a time. lol I went out an hour ago fired up the furnace and got the interior up to 80F and started the A/C. My thermometer recorded 47F to 50F which is pretty good in my book. Not sure what specs are. I'm impressed... Now to fix that blasted shroud.

[davidz71]

Sundance,
The Armstrong in my 31' Excella 500 1977 model could get the interior so cold you could hang meat in it. The Dometic Penguin on my '86 Sovereign 25' can't come close to it.