Truck has been to the dealer twice now- Once in September 2004 & April 2005. They say its ok!!!! Their test shows it blows out the vent at 43 degrees at an idle sitting at the shop. to me the a/c blows cool but not cold. On a 95 degree day the a/c barely keeps the truck cool. It seems like it gets to a certian point and thats it - barely tolerable on a 100 degree day. The kids faces are bright red from being hot.
- dealer drained and recycled both times
- same tempature weather truck has been on a short trip or a long road trip
Any thoughts?
Thanks,
Tim Ryden

 

Did they do a pressure test and a leakdown test? The system should hold pressure for at least 30 minutes or there is a leak. Does it blow cold right after they "fix" it, and they slowly get worse, or is it bad no matter what?

 

Thanks, 4x4not
Its bad no matter what. They did leak down test both times no problems found.
and it is not cold right after they fix it. It blows the same as always...

 

Are you running with "Max" air on? If not that could be the problem. The A/C can't keep up with pulling 100 degree outside air into the cab.

MikeyB

 

Buy you a couple ac thermometers at the auto parts store.(about $5 bucks each)Put one in a drivers vent and one in a pass.vent.Monitor temp.Should be close to the same(3 or 4 degrees and at least HALF if not more then ambient temp.This will at least inform you if its cooling.if its not and what temps it puts out on fresh,max,recir.etc. I leave mine in all the time.Helps take the guess work out of the scene.

 

I find a lot of complaints for "not cold enough A/C" is that the condenser is full of bugs. Remember, you got a lot of rain just like we did over winter and the bugs are really thick. Just take a garden hose and nozzle and squirt the water on the condenser until the bugs are cleaned off. I've seen a 15-20 deg drop in inside temps a few times. If the fins are bent that will restrict air flow thru the cond. I think auto zone sells a comb to straighten them out. Window tinting helps some too. Also look around the firewall area for missing body plugs letting in hot air. The hood should have a seal by the cowl to seal the eng comp air from getting into the fresh air intake. Make sure it is still there and sealing against the hood.

 

If you pay real close attention, you might have the same problem I have!
The A/C starts out fine, cooling well, then the volumn of air coming out the vents steadily decreases and is not as cool.

 

I know alot of new vehicles are coming with cabin air filters. My wife's Tahoe (sorry) was blowing cool, but could not keep up with cooling the truck. We had the cabin filters changed (we had no idea what was wrong) and now it can more than keep up. Ours was plugged with dirt (AZ) and dog fur (we bought used). Hope this helps.

Aaron

 

My neighbors Jeep did the same thing, two experts sayed it was fine, I put a pressure gauge on it and watched it, Idle was ok, bring the RPM's up to say 2200, like you were driving and it and the pressure slowly dropped until the low pressure switch cut out. We added a little more 134A and all is well!!

 

I had a similar problem with 03 hemi, the ac would cut out almost completely, after three trips to dealer they replayed the control panel and it worked fine. just a thaught

 

"The A/C starts out fine, cooling well, then the volumn of air coming out the vents steadily decreases and is not as cool."

This sounds like the coil is icing up.

 

coil icing up = low freon

 

i thought it was the other way around??? high level = freezing evaporator?

i know low level will cause excessive cycling of the compressor clutch..

and r-134a doesn't cool near as well as r-12 did...

 

nick,
Here's a thread that talks about freezing due to low freon.
https://www.dieseltruckresource.com/...5&pagenumber=2

MikeyB

 

I just had some A/C problems of my own, not blowing cold air during the middle of a long road trip. When I got where I was going, I booted up the laptop and read the chapter in the service manual about it.

The manual describes a performance check that can be done with the A/C system to determine if it is really operating up to specs. You need a couple of accurate thermometers to measure the air temperature outside the vehicle, as well as the discharge air temperature from the vents in the center of the instrument panel. Then you need an A/C recharge rig or something like that so you can monitor the R-134a pressures on both the low and high pressure sides while the system is in operation. The service manual then has a chart that lists the allowable range for each of the variables, so you can determine if you are getting everything you paid for out of the A/C system.

Turns out my 18-month old truck was simply a bit low on R-134a. The A/C pressure sensor wouldn't allow the Powertrain Control Module to energize the relay to power the A/C compressor clutch. Kind of odd for my truck to be low on refrigerant this early in its life! So I went to a dealer and they evacuated the system, and recharged the system with the fluorescent dye. We'll see if I've got any leaks when I take the truck into the shop in a few weeks for routine maintenance.