Skip the auto shop - Our mechanics make house calls

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

asked by on

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.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: No throttle response on 2012 dodge avenger

In the future, please include the motor size. Thanks. Your electronic throttle system consists of the throttle pedal assembly with an accelerator pedal position sensor, the throttle body which consist of a TPS (Throttle Position Sensor), throttle plate actuator,...

Q: F150 2006 thermostat spikes to hot after i am in 4wd for about 30 miles.

Hello, thank you for writing in. The vehicle is under more stress having to power all 4 wheels rather than 2. This will cause the engine to heat up quicker. You should be more focused on the cooling system than...

Q: fuel guage not working.

Hello, thank you for writing in. The fuel pump itself has a level sensor that may have been damaged during the process. It is physical float that rises and lowers with the level of fuel in the tank, and then...

Related articles

Rules of the Road For Iowa Drivers
Driving on the roads requires knowledge of the rules, many of which are based on common sense and courtesy. However, even though you know the rules in...
How to Avoid Back Pain in a Car
If you have back problems, sitting in a car for an extended period of time can be excruciating. Even without back problems, you could experience discomfort and soreness from...
How Much Does a Mechanic Make in Vermont?
Automotive technician jobs in Vermont have an average mechanic salary of $37k, with some mechanics earning a salary of $53k.