Aaair Conditioning Problem

[n6wmff@nstate.net]

Air conditioning is a simple system if you were to diagram it out on
paper yet it does have its quirks that can drive a person up the wall. 

If you put 12v directly to the compressor clutch, chances are the
electro magnet is burnt out. Check to make sure you have a good ground
first. If you do then you can get a replacement clutch. Most times the
compressor has to be removed from the car to do this. 

Dryers are not that expensive. You do have to break the system to
replace it. If the system still holds a vacuum then you maynot have to
replace it. If in doubt...REPLACE. If you charge the system and find
moisture collecting at the bottom of the dryer, its probably got water
or something in it, condensing to pull water from the outside air.

Yes, there is usually a high pressure switch that will limit the high
side so it cuts out and doesn't blow up the system. Conversely there is
also a low side switch that will disable the system when it gets to low
so that you don't burn up the compressor. 

If you are going to break the system for either a compressor or a dryer,
consider replacing the R-12 Freon with the newer 134a refrigerant. The o
rings must be replaced on the various connections, draining the
compressor of oil, replacing the reciever/dryer. Then putting in what is
called PEG oil, evac system and recharging with R-134a. Its not as cold
but its adequate. Some may not notice any difference at all. It might
only cool to say, 45 deg instead of a colder 40 deg? Its cheaper in the
long run as the last time I priced R-12 it was $45 for 14 oz can. R-134a
is about $5/lb.

Hope this helps with your primer on A/C?

Christopher Boles