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Q: AC Compressor Runs All the Time With No cooling in Cab

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2006 Dodge Ram3500 5.9l Cummins Diesel Laramie 151,000mi, Replaced 2 weeks ago, Condenser, Evaporator, Receiver/Dryer, Liquid Line (Orifice Tube). Added 7.1 ounces of PAG Oil/OEM Spec to to (Accumulator, Condenser, Evaporator and Compressor) system. I removed the dash and replaced the Evaporator and Heater Core as preventive measure. Inspected all HVAC doors and servo-motors all SAT. Pulled vacuum for 2 hours with no leaks. Added 30 ounces of R134a freon per OEM spec. and cab temperature was at 47f. Now cooling failed again and measured no pressure in system with compressor clutch engaged spinning when AC switch is on? There is only one pressure switch with this design. Compressor replaced June of 2015 <1yr old (Remanufactured from Chrysler/Dodge). Suspect pressure switch at fault and or compressor fault?

My car has 999999 miles.
My car has an automatic transmission.

A: If you are measuring no pressure in the sys...

If you are measuring no pressure in the system, then you have a leak and will have to find where the leak is. If you don’t have a leak detector, then you should obtain one or get a professional with the correct tools to help you. You may have a connection that is leaking or the compressor is leaking out of the front seal if you do not find any leaks then this is the most likely place to look and listen. If oil was added with dye at the last A/C service, then you can use a black light leak detector with yellow glasses. You can get this at most any auto parts store. If you can’t find the leak yourself or don’t have the correct tools, you should contact a professional, such as one from YourMechanic, to diagnose the a/c problem for you.

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