Durango air conditioning not working

[wjmitchell]

Hi, looking for help with my 2002 Durango SLT, 5.9 with rear A/C.

I bought the Durango new, A/C hasn't been as cool the last few summers as it used to be. But this year the compressor started making a banging noise and the clutch worked on and off, and this is where my problems started.

I took it to a new mechanic I've been trying out. I could have changed out the compressor myself but the system was fully charged, plus I don't have a vacuum. He recommended only changing the compressor, although the kits for sale on line online include the dryer, expansion valves, O-rings, oil, etc. Long story short I bought a pre-oiled compressor, the system held vacuum, and the mechanic ended up changing the compressor and dryer, plus had to blow out a clog in the low pressure line between the compressor and the expansion valve. But now it blows hot. He said I needed to change the climate control panel but I don't think that's it -- seems like he's turned a mechanical problem into an electric one (but if he's right and I'm wrong, I'll admit it).

Both front and rear A/C blow hot, although the rear may be a tad cooler (but it is further from the engine). When I slide the temperature control from cold to hot (or vice versa) there is a slight change in temperature, warm and hot. When the motor is cold, still no A/C, although air seemed cooler, probably due to no heat in the motor. Seemed to me that a blend door could have gotten stuck.

So, I pulled the coolant hoses off the heater core and looped them together. I had no heat or defrost, but I thought I could rule out the blend doors. No change, so I reconnected the heat. Then I pulled the three actuators, one at a time from below the steering wheel. They all reacted to changing the climate control settings, and rotating the flapper axle by hand didn't change the temperature; fan just blows hot. I saw two other directional motors up there and they responded to changes in the climate control direction.

Other symptoms: The low pressure line gets somewhat cool, the high pressure line off the compressor gets very hot.

Can anyone help?

[shorod]

Is the A/C compressor clutch engaging and staying engaged when you have A/C selected? If the compressor clutch is staying engaged yet the low pressure line never gets cold, have someone check both the high and low pressures to see if the charge is not sufficient or if they indicate some other issue. Have you inspected all the fittings for any signs of leaks?

-Rod

[wjmitchell]

Thanks Rod. I have leak detector dye in the system, and I have the light and glasses, but didn't see any leaks. The compressor stayed on the whole time. I checked the charge with my cheapie gauge and it was on the low side so I tried adding a short boost of refrigerant. Now the compressor cycles on and off, about 5 or 6 seconds at a time. No change in temperature.

I'm think of adding a more 134a tonight. Short of starting to take the system apart, I don't know what else to do.

[shorod]

Sorry for the delay in responding. I didn't notice there were any new posts until this morning.

I'm not familiar with the 2002 Durango, but maybe there is a heater control valve or something that should normally close when A/C is selected, but yours is not closing, therefore you are getting coolant flowing through the heater core all the time.

Also, regarding the compressor now engaging after adding more R-134a - this seems like a sign that the charge is not correct. If you are able to confirm there isn't an issue with an open heater control valve or similar, it might be in your best interest to have the system evacuated and recharged. That process will check for leaks as well. Since the compressor was recently changed out, taking it back to the same shop and requesting "help" with the expense would be warranted.

-Rod

[brcidd]

Why is it that every time I hear of a Dodge/Chrysler a/c issue, I immediately think the evaporator is leaking? Been quite a few in my life....