2009 Dodge Journey A/C Not Cold – Strange Pressure Readings

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I had an interesting problem vehicle in my shop. It is a 2009 Dodge Journey with the 2.4L engine and an electronically controlled variable displacement compressor. I am working on it after others have failed to repair the system.  No one can tell me how the original compressor failed or why they replaced it so my assumption is that it was locked up or was leaking.  The compressor has been replaced twice, the drier once and the expansion valve once. All aftermarket parts except for the second compressor, new Denso 471 0804.  The condenser has not been changed. If the original compressor failure was due to a locked up or noisy compressor the condenser should have been changed along with a lot of other necessary work.

Here are the conditions and pressures.

Ambient temperature  is 80 F . Humidity is 60%. System fully charged and engine idling. Low pressure is 80 – 85. High pressure is 100. Engine idling for just a few minutes and the pressure release valve pops open. No lines are hot or cold. There is some heat building in just the compressor case.

No engine codes relating to a/c.

Ambient temperature and evaporator core temperatures sensors read current outside temperature.

Pressure switch reading matches scan tool data.

Have power and ground to the variable displacement solenoid/valve.

Disconnecting variable displacement solenoid/valve nearly equalizes pressures.  Low 104, High 109. Doing so will also set a code P0645.

Control Voltage across the terminals at the variable displacement solenoid/valve is varying. Ranges from near zero volts up until about 10.5 volts when the pressure releases.

If the system charge is low the high side pressure will drop to about 50 and the low side is still at about 100.

I am strongly suspecting a restricted condenser and or drier assembly but I have never encountered a system where a discernible temperature or pressure difference cannot be found.

I recovered the refrigerant with the plan to add some refrigerant on the high side with the hose from the compressor to the condenser disconnected and plugged. That would allow me to get a feel for what kind of flow there was through the condenser and the drier. Both gauges on the machine were in vacuum.

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I loosened the nut holding the compressor discharge line to the condenser and refrigerant started leaking out! The green coloring is dye and oil mixed together that came out with the refrigerant.

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I had to wait for the refrigerant pressure to bleed off before I could continue with my test. At this point there was no real need for the test but I was there anyways and why not?  Using a rubber plug and my thumb I sealed off the compressor discharge hose fitting. I added refrigerant on the high side with my charging station until I had about 70 psi of pressure and absolutely no refrigerant came through the open condenser port. As I had originally suspected the condenser was restricted. Well actually completely blocked. Maybe just luck but I have never seen a completely blocked condenser before.

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