Hi,
Fuse fine, compressor clutch turns (not frozen,) Dash dial performs as should. Yet when I engage the A/C.... nothing. Clutch will not engage, no noise, no up in RPM...zilch. I do know that if the refrigerant is low or empty, this can happen. : can this possibly be the issue with the stock A/C in my Blazer?
Thanks~

 

Your most likely out of refrigerant. With the ac controls in the cabin set to max cold put a jumper wire on the low pressure sensor connection. If the clutch engages and runs the compressor you have leak and are out of refrigerant. The low pressure sensor is the on the dryer which almost looks like a mini half barrel with an insulating cover and a couple of lines running to it. Unplug this electrical connection and put a jumper on the wire end of the connection not on the sensor. Recharging with a leak and trying to find the right miracle fix in a can could cost more than having a professional find your leak. Then you will know if fixing the leak is in your budget or if its worth doing. Throwing r134a at a leaking system is as fun as burning your own money.

 

These compressors are notorious for leaking, theyre refered to by A/C techs as "Belly Leakers" look for damp oily residue toward the middle of the compressor down low, the aluminum housing corrodes and the corrosion eventually finds its way into the sealing area and allows the refrigerant to leak out, if you do confirm that the clutch will engage with the test that Lancealot explained then my next step would be to push the valve in on the low pressure port and see how much pressure comes out, just a quick push and release is all you need if you dont have a gage, obviously be careful not to be in front of it and dont inhale the stuff, but if you get a decent relief like letting air out of a truck tire then your leak may not be that bad and you could get by for a while by adding a can here and there but as mentioned, its like setting fire to your hard earned money and definitely dont use the stuff with sealer, it causes more problems and almost never fixes a leak, also many shops wont hook their machine up of they see sealer residue on your service ports because it will plug up the machine. If you only get a little puff or nothing at all then the system is totally empty and probably has outside air and moisture in it by now, if thats the case it needs major repairs.
Good luck

 

Thank you both! As the weather here in NE PA being uncooperative, I only hit the problem today.
Lancealot: Jumped as per your advise, started smooth, no noise, ran as should.
DimeBlazr: "Belly Leakers" haha, good one! No, nothing in the way of even a trickle, bone dry.
I am now on an adventure / mission to get this up & running by July. I wonder though, this vehicle sat for years under a tarp (only 67K on it,) if the refrigerant dissipated while in hibernation. I will go / burn $20 for a can and see if it holds for X amount of time, perhaps I will be able to make a better decision.
Thanks again, both of you...for the needed assistance.