Warm A/C

I bought my 06 a couple months ago and never tested the A/C. We had a couple warm days and of course I find out that the A/C is blowing warm.

The light stays on solid, and does not blink. When I press the button, there is no change in sound or RPMs from the engine, nor any change in temperature at all. Unless the A/C compressors on these things are really quiet, I dont even think the compressor is engaging. Fuse under hood is intact.

I have read about alot of people's compressors failing prematurely, but did this not end in strange sounds from the compressor, not none at all?

Not sure where to start troubleshooting this first. Truck only has 60k KM (37k Miles)

Thanks

 

Hmm. Mine did that and I took it in to check the freon levels. It was empty. So had it filled. Problem solved

 

Probably just needs to recharge the system

 

I hope thats all it is, I guess I will try this week to get it in. Anybody ever used a kit and done it themself?

I have a 1999 ZR2 Blazer that has AC that blows freezing cold and it hasn't had a recharge in over 10 years.

 

I guess my real concern is that I cannot hear the compressor come on

 

check your fuse. It's located inside the cab behind the dash.

 

I see no fuse for AC in the in cab fuseblock, only under the hood, and that 10A fuse is intact.

UPDATE: So, I can see the compressor, belt is spinning around the pulley, but center is not spinning. If it is like my Chevy, when the clutch engages the center of the compressor pulley should be spinning as well. This does not happen either while in defrost or AC.

If the system is void of R134, should the compressor still not engage?

the compressor spins freely by hand when the truck is off, so it is not seized.

 

The compressor will engage regardless if the system has lost its refrigerant charge or not. If it has lost its charge, obviously there is a leak somewhere..perhaps very small, but a leak nonetheless.
You should be able to hear the compressor clutch engage when you fire up the AC or defrost... have someone help you so you can listen nearby the compressor maybe?
Hopefully it's just a fuse problem or something similar keeping the signal from getting to the compressor...

 

This is what I thought as well. I checked, the compressor is indeed not engaging when the switch is pushed (Or when in defrost). Fuse is intact. The compressor spins freely by hand when the truck is off, so it is not seized, but the magnetic clutch is not engaging when it should.

 

If the system is overcharged or undercharged, the compressor will not engage.
The system contains not only refrigerant, but also lubricant, and without lubricant, the compressor won't last 10 minutes.

Take it to a shop. Do not just try to recharge it yourself.
If the system is discharged it is discharged for a reason and there is likely a bad seal. The shop will draw a vacuum on the system to clear out the remaining refrigerant and any air/moisture that might be in there, and they'll confirm that it holds vacuum. If not, they will be able to locate the source of the leak.

They will also be able to recharge it properly.
Dumping can after can of "freon" into a system is not a "proper" recharge, especially if the system is so low that the compressor is not engaging.

 

Oh really... oops. Makes sense given the lubricant part... I assumed the compressor would work either way. I had a '03 Honda that had lost its charge, and I'm pretty sure the compressor still kicked in/out.. but maybe not.

 

It depends on the level.

The charge can get pretty low before it kicks off.
The sensor is on the low pressure side. When in the "off" state, the two sides equalize, when on, the pressure on the low side drops to less than half the "static" pressure, and the compressor needs to run at this pressure.

If the charge is low, what will happen is the compressor will cycle off and on. This is also normal operation, so you have to pay attention to what's happening at the vents. When the evaporator gets too cold, pressure drops, and that causes the compressor to cycle off... kinda self-regulating to keep the system from getting too cold and icing over.

So when the charge is "only a little low" it'll cycle, just more frequently than normal.
Compounding this will be that a low charge level will often result in cooler evaporator temperatures, which again, increases cycling.

But when the system is so drained that the compressor won't even kick on, it's pretty close to done.
Definitely time for a pro at that point because it's lost too much refrigerant and lubricant to be safely replaced by a DIY kit.