Re: [DML] Re: AC system compressor doesn't cycle, high discharge pressure

["Tom" <tomciodmc@xxxxxxxxxxxxxx>]

From: "David Teitelbaum"
<SNIP>You could also have a low presure
switch way out of adjustment. The compressor MUST cycle. Try adjusting
it. It is the screw in between <SNIP>

NO NO NO, Do not touch the switch!! C'mon David... If the pressure is too 
high on the low side then the switch will not activate. The switch doesn't 
control the pressure, it's the other way around. The switch should disengage 
the compressor when the low side pressure drops to between 29 and 35. When 
the pressure stays above 50 the switch will have nothing to do with it.
Dirty or plugged condenser (the thing in front of the radiator) will cause 
the high side pressure to rise. Plugged orifice will cause low side to be 
too low and high side to be too high. Open (broken, missing) orifice will 
cause the low side to read high and high side to read low.
In this case the high side is a bit high, but without knowing what the 
outside temperature was it's difficult to say... it might be ok. The low 
side is way to high. This to me would indicate a problem with the compressor 
or overcharged system. When there is too much refrigerant in the system 
there is just no place for the compressed freon to go. It is forced through 
the orifice at high pressure and keeps the low side pressure too high 
causing the evaporator to freeze over. 36 ounces of R-12 is correct but that 
applies to factory system in a D. That means that if you have shorter hoses, 
smaller accumulator, bent/damaged condenser, too much oil, etc. then it 
would be too much for the system.
I would recommend charging the system with less freon. BTW, make sure that 
you are really putting 36 ounces in there. Is your measuring system correct? 
If you are using a scale, is it good? And the main thing is - Are you 
putting 36 ounces by weight or 36 fluid ounces?? It's suppose to be a weight 
measure. Or just switch to the metric system and use 1000 grams of R-12 :)

Good luck!

Tom Niemczewski
tomciodmc@xxxxxxxxxxx pl -> www.deloreana.com
VIN 6149 (in Poland!)
Save the dream so you can live the dream...





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