I have a 1995 Dodge Ram 1500 with a 5.3 L engine. My A/C stopped
working gradually over about 2 weeks. In other words it cooled less
and less with greater frequency. I checked the High Side pressure and
it measured 320+ therefore I did not add any freon. I was told that it
was already too high indicating that adding freon would not fix the
problem. Can anyone tell me what the pressure should be on the high
side? Or what else I could check. The compressor no longer kicks in.
On a 80 degree day lowside 29 psi and 215 psi on the high side. With out
knowing the low side psi it is a SWAG. If both high and low sides are high
possibility of an over charge, condenser cooling fins clogged with dirt or
the cooling fan is not working.
I measured 100 PSI on the low side and 350 PSI on the high side with
about 1000 RPM and 90 degrees outside. I have never added freon since
I bought it in 1997. If the condenser cooling fins are clogged would
there be an outward indication that I can see?
Nope you can not generally tell if they are clogged up with dirt. I have
access to commercial products for cleaning AC systems and use a spray
product to clean both the condenser and evaporator.
There are several other things that can also cause the high readings on both
the low and high side. Such as air in the system, a bad TXV, contaminated
compressor oil or just over filled.
In any case if cleaning does not work then the system needs to be evacuated
to 500 microns and refilled with the exact amount of refrigerant specified
for your system. Check the compressor oil for contamination and add the
Unless you are familiar with working on AC systems have it done by a
certified automotive tech that has been trained on automotive AC systems.
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