samger2

I'm just wondering what's cold? I mean I've replaced the compressor, the condenser, lower a/c line, my orifice tube...all the associated o-rings...had it recharged...but it still blows "cool". I always read these car ads where people claim "a/c blows ICE COLD"...I can have my a/c running on full blast for half an hour while I'm driving...yeah, it gets cool in the truck, makes me comfortable...but there's never a point where it's ice cold. I've been in other vehicles where I've had to turn it down it's gotten so freezing...there's never a time my truck does this.

What am I missing? How can I achieve this mystical "ice cold a/c" that I've heard so much about?

Oh...by the way, it's a 1996 Z71

therewolf

As long as you're getting the proper heat transfer, your system should "blow ice cold". What's really happening is your A/C system is drawing the heat OUT of your vehicle interior.(I've also found it easier to troubleshoot remembering this principle.) There's only a few possibilities which are robbing you of your joy.

1)Close ALL your windows. With a window open, your system is trying to draw heat out of your car interior, AND THE REST OF THE UNIVERSE. The smaller area to be cooled, the more efficient the system.

2)Inside your passenger compartment, the freon is drawing heat away by getting boiling hot, then being moved to the exterior of your car to be cooled and returned to repeat the cycle. How are the fins on your internal coil, are they covered with dust? That might be interfering with heat transfer. If the freon doesn't heat up, no heat is being removed from your passenger compartment. I'm sorry, the coil's like a small radiator under your dash, and it's not easy to get to, but you need to (gently ) clean(and hopefully vacuum) it.

3)Your external coils may be covered with dirt and dust, once again interfering with your heat transfer away from the vehicle to cool the freon completely and complete the cycle. The external coil appears to be a thin radiator in front of your regular radiator. Dirt in the fins will cause you grief.

4) You've replaced the compressor and recharged the system, so the last thing on the list would be a blockage in the freon lines themselves. We'll assume the lines are free of any blockages, because that should have been taken care of when you evacuated the freon and recharged it during parts replacement.


Remember that dust and dirt act as a super-insulator, in as much as they block successful heat(thermal) transfer.
"Ice cold air" may be as simple as(gently) hosing the dirt off your A/C cooling fins. Assuming you're holding a charge, and the freon's circulating properly, dirt(On a 13 year old system) is the first suspect.

Once you've got it right, you'll have cold air in seconds, and you won't wonder, you'll KNOW.

shawnvw

Are you sure the amount of refrigerant is proper? have too little or too much will cause a "cool but not cold" condition

MDTAHOE

You need to put a thermometer in the center vent with low fan speed and let us know what temp it is blowing and what the outside temp is at that time.

99chevy7.4L

well just for reference my 99 C3500 blows around 40 out the vents but after an hour or so its down around 35-38.

roscowgo

Mines cold enough that I have to turn it down/off after awhile when its 90-95 outside.

samger2

ok gang. I'm gonna start by looking at the fins on the coil under the dash and seeing if they're dirty. Next chance I get I'll also put a thermometer in the dash vent to see how cold it's really getting. Thanks for the input.

therewolf

Hose off you radiator and the A/C coil in front of it, too.

samger2

Both the radiator and a/c condenser are brand new, so they SHOULDN'T be part of the culprit.

larryboy58

Was the system properly evacuated. Meaning Did who ever did the work leave the vacuum pump on the system long enough, and was the oil in the vacuum pump fresh? If not it may have not pulled it down enough to completely remove all the moisture from the system. Was the recharge done as a gas or liquid? And was the charge weighed in or just "dumped in" And to add to river eye's reply was the a/c switch set on "MAX" or just a/c during the recharge? And was there a leak check performed on the system after the repair to be sure the system is "tight". And what happened to make you change the parts to begin with. Was it just not performing like it used to or was there a parts failure, such as the compressor failing. My point is if it was a severe compressor failure there could be stuff floating around that could clog the metering device (orifice), or impede the performance of it.