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

asked by on May 13, 2016

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.

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


Experienced Mechanic?

Earn up to $70/hr

What others are asking

What makes the check engine light come on?
The drive complaint you described seems to be an engine misfire, which can be verified by scanning the cars computer for an error code. If you get a code P0300, P0302, P0304 or P0306 then Jeep has issued a Technical...
What does it mean if the Brake System Light comes on in the dash?
Of all the safety systems built into your car, the brakes are the most important. While the Brake System indicator should come on during startup, it should go out after a few seconds. If it does not, or if it...
Car not staying in gear
Hi. You did not mention if you had an automatic or manual transmission. This can be caused by two different problems. The first cause could be that the transmission mounts allow movement of the transmission and knocks it out of...
Car not starting in temperatures over 80 degrees
Hi there. This can be a common issue that vehicles encounter when the temperature outside is warm or if there is a sticky starter solenoid. The solenoid will stick even if sufficient current is applied to its switch. I'd suggest...
A/C fuse busted when car starts to run
Hello there, thank you for asking about your 2004 Honda Civic. You should try to disconnect the AC compressor and run the car as if the AC compressor is plugged in to see if the fuse blows still. If it...
Driver side rear shock is leaking oil the set only has about 2500 miles on them? they are coil over shocks.
Hello. A shock is not always bad, but if you see some residue oil leaking from the shock then it may not be functioning fully. If you see a really wet and dripping shock, then it should be replaced. The...
Ha an alignment.. 04 pt cruiser still pulls to the right hard
If the alignment has not enough positive caster it will not return to center as it should or if you have a binding rack and pinion or tie rod ends it will also cause the same problem. If alignment is...
2003 Toyota Camry radiator fans are not coming on when the car is started but one fan runs when the temp sensor is unplugged.
The radiator fans are controlled by the Electronic Control Unit via the fan relay. The fans are supposed to come on when the engine reaches a certain temperature, or when the AC pressure comes up. If the car is overheating...

Related articles

The Best Used Cars to Buy If You're a Dog Trainer
If If you are a dog trainer, you expect a lot from your vehicle. You want a ride that is safe, roomy, and of course, dog friendly, since your training operation will often mean that you need to transport the...
The Best Used Cars to Buy If You’re a Massage Therapist
If If you're a massage therapist, one of the cornerstones of your business has to be that you don’t keep your clients waiting. That means you need a vehicle that’s reliable. You also will have to move your gear, including...
The Best Used Cars to Buy If You Have a Tiny Parking Space
In In many cities parking spaces come at a premium, so you only want to purchase one small space. This small space will end up dictating what vehicle you purchase, so we’ve rounded up some great candidates. Must-haves Arm yourself...