2014 Altima SL with 149K miles
AC has trouble maintaining cool air.
Seems to hold a vacuum fineCompressor clutch engages
left and right blend doors seem OK
Intake door motor seems OK
Control panel and control module seem to work fine
Relay and cabin sensor seem fine
Is it possible that the compressor is bad even though The clutch engages and seems to Maintain pressure?
I just experienced the same problem with my 2013 VW passat at similar mileage. After many head scratching, I found that theres this fragile electrical parts called a solenoid valve on the compressor that control the refrigerant flow. How it works is that the battery gives a current and tell how much to open the valve. And often what happens is that it either is stuck open all the way or it wont open enough. Anyways, these go out quite easily. So i suggest replacing them first. It only cost 50 buck or so. My car has intermittent cooling and it will only go down to 60 degrees. After replacing the solenoid, it consistently blows 40 degree air. Good Luck
BTW, I used RKXtech valves. They seemed popular for this replacement. They make a wode range of valves. But make sure to check your compressor model label on the compressor itself because it's very easy to get the wrong part
This is a little too much information, but u can test out the solenoid valves by taking them out and running the rated voltage through it. it should click and open when power goes through. The other way involves measuring duty cycle of the valve when the compressor is running at max. I don't like to mess with electrical stuff and since its just 50 bucks, might as well replace it.
Evacuate the system and get a reverse scale. Rent a setvof manifold guages, put straight R-134a into the system. The capacity of the AC system is under the hood, on a placard, usually on the right side. If you've never recharged the air conditioner, after 10 years, it's probably time for a recharge. All car-based AC systems leak a tiny bit of refrigerant over time to keep their seals lubricated.
There are high and low pressure sensors within the AC system. If the pressure drops below a certain threshold, the air conditioner will shut off to protect the compressor.
What are the system pressures? Refrigerant level is critical in modern AC systems and with a variable displacement compressor cannot be accurately determined by pressure. How was the system recharged - evacuated, vacuum pulled, and the correct amount by weight installed or was additional refrigerant just added to whatever was in there?
Thank you for the response. However, we have tested pressures with a gauge and recharged the system. Low pressure hose varies from hot to mildly cold and back to hot again. The compressor clutch is engaged and spinning the whole time.