Have a 2002 Durango and the A/C is just not keeping up. The pressure are all on the high reading on both Low and High pressure sides. I have replaced Condensor, Dryer, Compressor.....pretty much everything except the lines and the blower motor. The pressures do drop above 2000 RPM towards normal range but never make it. At idle I am getting 60 on Low and 110 on high. Any suggestions? been looking through forum and nothing has stood out at me.

 

Either a blend door or expansion valve.

 

Blend Door, where is that located? not sure of what you mean by the blend door. I have found a filter that I found at the fire wall but it is just a dust/particle filter.

 

Have only dabbled in AC problems. Don't forget the evaporator? You may also want to try this forum: http://www.autoacforum.com/

 

blend door is inside the hvac box behind the dashboard, as are the directional doors

 

The blend door mixes (blends) air from the ac evaporator with air from heater core per your setting of the temperature control ****.

Here's one way to test if it is part of the problem: start your rig in the morning (or anytime) when it's cold and then turn on the AC. If the air from the ducts cools when you turn on the ac, and then warms up on it's own as the engine warms, then you may have a blend door that is not completely closing off the heater core air.

This also shows up when you simply want to use the HVAC vents to blow outside air without AC, say when it's about 65F outside, but the air coming from the vents is up in the 70's.

The heater unit can be a bear to work on, and I've read of some people installing a hot water bypass to completely bypass their heater core during warm weather, so they can get their duct temps to cool off.