I'm hoping some of the membership here can help me figure out what the cause of an underperforming air conditioner is.
Vehicle is an 01 Dodge Durango, 4.7 V8 with the dual climate controls and split heater/evaporator behind the back seat. The issue is, air conditioner compressor comes on, runs continuously, but does not cool well at all.
We bought this vehicle used a few years ago, and it appeared that the compressor had been replaced, but I'm not certain. I do know that the electric fan was bad and the engine driven fan clutch was also not working correctly, so I replaced them both.
It was low on refrigerant, so I added a couple of cans and it worked fine. Every spring I'd have to add refrigerant, and often a bit more in late summer.
This spring I was moving and when the A/C wasn't working, I presumed it needed refrigerant again. I noticed it wasn't as low as usual, and it never did work very well at all. So. Apparently, low refrigerant isn't the cause this time.
As I stated, cooling performance is very poor both from the front vents and from the vents from the rear also. My understanding is there are 2 expansion valves on this system, so I'd not think both have gone bad, but air conditioning is not my specialty.
As I recall, the low side pressure on a 95 degree day was about 42 PSI. I did not check the high pressure side, so I don't know what it was.
My questions are, what should my low and high pressures be on a 90 degree day? How can I determine if the compressor or expansion valves are bad? Is it possible something else is restricting flow? If so what do I need to look for.
The high pressure side from the compressor is not near what I would call hot, and the return side is not nearly as cold as I normally find.
If anyone can tell me where to start checking, I'd be quite greatful.
Thanks in advance.