AC not cold all the time
 

Hi, The wifes 2006 Durango AC started feeling a bit warm so I checked the refrigerant pressure to find it high (55 low side). This was odd since it has never been touched from factory. I suspected the expansion valve so I replaced it and the dryer. It only took 24 OZ of refrig until it got to 45 psi. It calls for more but I stopped adding. It works great at 45psi but as soon as it gets hot it increases to 55 again and doesn't blow cold. Is there something else that could restrict the flow of refrigerant besides the expansion valve? Thanks in advance

My 2007 will sometimes blow warm air even though the a/c is on. I have to shut it off and then turn it back on for it to blow cold air. It seems to be only one of the vents will do it so I do not think it is the blend door....not that this helps your situation,
FF

Here is a TSB,I don't know if it would help.

SUBJECT:
No A/C Or Evaporator Freeze Up On Long Trips With Blower In Low Speed Position
OVERVIEW:
This bulletin involves adding a resistor 470 ohm resistor in the evaporator temperature
sensor signal circuit.
MODELS:
2004 - 2009 (HB) Durango
2007 - 2009 (HG) Aspen
NOTE: This bulletin applies to all HB/HG vehicles with A/C (sales code HAA or HAB
or HAF). This bulletin does not cover the 2009 HG HEV vehicle.
SYMPTOM/CONDITION:
The customers may experience poor A/C, little to no A/C operation or reduced airflow from
the instrument panel vents. This condition often occurs after a extended drive cycle
(greater that 2 hours) with the A/C on and the blower speed is set to the low position. Once
the vehicle is shut off or the A/C is turned off for approximately 2 hours the A/C will operate
normally.
Adding the resistor to the evaporator temperature sensor signal wire allows the A/C
Compressor to cycle at a higher temperature more frequently to avoid this condition.
DIAGNOSIS:
Using a Scan Tool (wiTECH™ or StarSCAN®) with the appropriate Diagnostic Procedures
available in TechCONNECT, verify all A/C systems are functioning as designed. If DTC's
are present record them on the repair order and repair as necessary before proceeding
further with this bulletin.
If the above condition is present, perform the Repair Procedure.
NUMBER: 24-004-10
GROUP: Heating & Air
Conditioning
DATE: April 7, 2010
PARTS REQUIRED:
Qty. Part No. Description
1 68081530AA Kit, Resistor
Kit includes; 1 470 ohm resistor, 2 wire shrink wraps and
2 splice crimps.
REPAIR PROCEDURE:
1. Remove and disconnect the ATC or MTC control head. Follow the detailed service
procedures available in DealerCONNECT/TechCONNECT, Refer To Group 24 -
Heating & Air Conditioning > Controls, Front> Controls, A/C & Heater Removal
Procedures.
2. Using the wiring diagrams available in DealerCONNECT/TechCONNECT locate the
evaporator temperature sensor signal wire. Cavity 10 of the C2 black 12 - way
connector for ATC systems. Cavity 2 of 20 - way black C1 connector for MTC systems.
3. Measure 76mm (3 inches) down from end of ATC/MTC connector and cut the
evaporator temperature sensor signal wire.
4. Using the 2 splice crimps and 2 wire shrink wraps from resistor kit p/n 68064996AA,
splice in the 470 ohm resistor. Follow the detailed wiring procedures available in
DealerCONNECT/TechCONNECT, Refer To the Wiring Tab > 8W-01 - Wiring
Diagram Information > Wire > Standard Procedure.
NOTE: Be sure to use the splice crimps and shrink wrap on wires and resistor.
5. Install the ATC or MTC control head. Follow the detailed service procedures available
in DealerCONNECT/TechCONNECT, Refer To Group 24 - Heating & Air Conditioning
> Controls, Front> Controls, A/C & Heater Installation Procedures.
6. Using the wiTECH™ or StarSCAN® erase all DTC.

Thanks for the info. I've seen that TSB but I don't think the evap coil is freezing. Somethings causing the the pressure to be high (or not drop enough). Does anyone know how to test blend doors?

It only takes a 12 oz can to get it from 0 to 50 psi. I know this is not enough refrigerant. I can't measure the high side but I suspect the compressor is not processing as it should. I've only seen a compressor fail by producing zero pressure but can it fail in this manner? How can I be sure because they are very proud with the pricing.

Thanks again in advance.

Sounds like something is clogged before it gets to Evap. Expansion Device my be faulty and stuck. .... ? if you do end up needing new ac parts shoot me a PM (I distribute them for manufacturers and can take care of you) ....

Its Clutch making weird noises? Property engaging and spinning? Sounds odd.

Added to friends' list :icon_santawaving:

I had a similar problem with my 2005 Durango. I found the main radiator fan was not blowing any air on the compressor. When the fan is operating properly it will blow hard, if not like mine was there was no air movement at all and the fan was turning slowly. I replaced my fan clutch and it fixed my issue. Be careful, I swapped my fan clutch with a unit from a parts store and it made it worse. Come to find out mine needed the Max Cooling version. I had to order from Dodge. $175.00 I put it on and it works like a champ. Good luck to you. Hope this helps.

This may be a dumb question but what is the refrigerant capacity on your AC label under the hood? Actually, your symptoms sound like an overcharge OR there may be waaay to much oil in your system. Speaking of oil, you have to pay attention to the cans you buy off the shelf at parts stores. They sell cans that have 134A AND OIL in them too. You may just have saturated the system and it can't transfer heat through the oil....clear as mud? :icon_idea1:

On a bunch of different models i've run the selector all the way to hot, let it settle at stop then run it back to cold. You may need a calibration or a reset with the scan tool.