I know this has been beaten to death, but is there a specific temp that the A/C air blow out at. Does GM mesure the air and say 'Hey it's at xx degrees so it's normal." How do they measure the temp? Regular Thermometer? Reason Why I ask is that I have a 2004 gasser that I think is not cold but dealer insists it's normal. Under the service order, It states "Customer states A/C is not cold Check AC operation, system is blowing 47 degrees from vents. This is acceptable for GM Specifications." To me, 47 degrees is not that cold. I know there was a TSB out on this a while ago, but I thought it applied to diesels only. Summers coming and I want some decent AC. If there is anything I can do to fix or test this myself, please fill me in. Thanks.

Try another dealer. 47 degrees and it's not even June yet! I too have some issues with my A/C but I have to wait until the outside temps are high enough to verify if there is a problem still. There is a TSB on it which I will mention on my next service visit when it happens again. In the meantime, get a digital thermometer and check the readings in normal versus recirculatory modes in freeway versus city driving. I think the optimal number you'll want is about 40 degrees. Also, note the outside temps when your record your readings.

You need to find out how they test it. For instance Ford tests it on 2nd from highest fan setting in the middle vent. They claim that on high, the air is moving too fast to get cooled properly. Sounds great in theory, but when its 100+ degrees you think I wont have the air on high? If I get 47 degrees out of this truck I will be happy. The Ford never got under 70 at the vent.

I'm going to do more testing with a digital thermometer and compare that to the ambient temps. I still think it's too warm to be called "A/C".

Usually in the 80's I shoot for an outlet temp of 42* higher 80-90's is usually 44 lower 80's some vehicles I have 35-38*. doing the test the way I do, 47 would tell me its either 1/2 pound or so low or another problem.

The way I run the check is letting it run with the fan on a medium speed, recirculate, I allow it time to cool down cabin air and then take the test usually from the center vent.

Had mine in the shop several times trying to get cooler...they replaced the accumulator and pipe under one tsb...triedadjusting refrigerant another time..third time did nothing....found another dealer..adjusted actuators and refrigerant..dropped my temp 10 degerees......i think it ended up at around 45 out the vent..

I'm thinking of taking my 04 LLY into the GMC dealer this summer also. I noticed last summer that it didn't seem to get the cab cold enough in the hot summer weather (not that it gets extremely hot here in Oregon). I noticed that my 94 S-10 pickup has alot colder air coming out of the vents: it's over 10 years old with 185000 miles. So a brand new truck should be just as cold one would think.:cool2:

On R-12 units, the exit temp was about 55°F for a properly charge and running unit with the blower on high and bringing fresh air and the engine running at 2000 RPM's, at 85°F ambient temps.

The new R-134A units may have different parameters, but I'll bet they are close to that.

Most Automotive style A/C units are 5 ton (60,000 BTU) A/C systems. There is a lot of heat build up in the cab of a truck when setting in the sun. On a cold sunny day, I've had the inside of my cab reach 80°F when it's been in the 30's outside. That's a 50°F rise just due to radiant heat.