Re: 2001 Ford Taurus Air Conditioner

You need to start with the basics. Diagnosing refrigerant fill level
can be done ONLY TO A DEGREE through pressures. You have to read high
and low side both, you have to understand how these are subject to
ambient temperature and humidity. Readings should be taken at about
1750 rpm and allowed to stabilize. Pressure readings WILL mislead
you regarding the level of refrigerant charge should there be any of
the following situations:

1. A weak compressor
2. Air or moisture in the system
3. A restricted expansion tube/valve or any restriction elsewhere.
4. A missing or broken expansion tube or wide open expansion valve.
5. Poor air flow through the condensor.
6. An evaporator core coated with a mat of dog hair or leaf mulch.
7. Some kind of bogus "refrigerant" has been put in the system.
8. There is a gross excess of refrigerant oil in the system.
(Compressor a little noisy? Add more oil. Still noisy add STILL more

For all but the most routine service the only way to go is to evacuate
the system -- taking note of how much refrigerant was removed -- and
then refill it to factory spec. This requires a professional's AC
recycling machine. A good recycling machine will take care of air or
moisture contamination. If should produce reasonable pressure
readings ON THE HIGH AND LOW SIDE BOTH and cool well. It should
satisfy the electrical controls for the compressor also. If not, see
#1, #3-#6, #8.

Occasionally duct work or hot/cold blend door problems are the
culprit. .