4 Wheel Drive/SUVs: A/C Clutch not engaging, r 134a refrigerant, cummins diesel

Question
I have a 2006 dodge 3500 5.9l cummins diesel.
I have no air conditioning. My indicator light comes on in the dash. the fan blows, but no cold air. I noticed my a/c clutch will not engage. I checked the 2 wire plug for power with the key on and there was none. all fuses are good. If the system was low on pressure would it cause this problem?

Answer
Yes, there is a low pressure cut out switch in the A/C line before the compressor itself. if the refrigerant pressure is low it will not engage the compressor so no damage occurs. The best way to check it is to go to your local auto parts store and buy a R-134a gauge. You can do this at home since R-134a refrigerant is available to the public. The gauge has a short piece of hose and a quick connector on it and it will only fit on the low pressure fitting. You won't be able to connect it the wrong way...have no fear. The gage is color coded and it will say on the gauge what it should be. Check it with the A/C running on MAX A/C and fan on full power(high). This will tell you right away if it is a low refrigerant charge and the gauge should be less than $20

Hope this helps and if it is low, let me know and I can talk you through adding some freon to get it working again

Matt