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A/C Not Coming On When Hot Outside

D

dandan

Charter Member
SM 2003
Full Member
Joined
Mar 3, 2002
Messages
644
Location
Central Texas
This has happened twice recently. What's going on?

Pretty hot day (near 90) here in Central Texas. Haven't been in Big Blue in a while. Inside is hot. Start the car with A/C on and recirculating air with fan on 5. The air blowing out doesn't get cool for 10-15 minutes.

If it's not hot outside or after 10-15 minutes, if you turn the A/C on full blast you'll freeze your nads off. So it's not a faulty A/C unit.

You should be feeling some cool air quicker than 10-15 minutes. I understand the car may take a little to cool completely down.

Anyone else have this experience?
 
I had this same problem with my AV. It was the line between the condensor and the firewall. The fitting which connects the two lines together came a little losse and leaked out all of the R-134a.
 
I still have all the refrigerant. On cool days, the A/C kicks on almost immediately.

I had another incident yesterday in QAustin, Tx as the temp was 90+. Turnjed on the A/C to max, recirculating air and the thing would literally pump hot air.

Changed to outside air and the fan speed would decrease w/o me touching anything.

Service Manager at the dealership is at a loss at this time. I have to take it in when it's hot outside again (today it's 80-85).

I can't believe I'm the only one that's had this experience.

gandolphxx, ygmn, goo929, anybody? Help!
 
Strange, the only thing I have noticed as spring is upon us [93] is that it blows warm air for about a minute, and then starts the arctic cycle - I had the reverse problem in the winter - would only heat when set to max, then would be ok.
 
I was on the phone with the Service Manager as it was happening and it certainly was more than a minute, more like 7-8 minutes. Actually, not until I started moving did it start to get cooler.

Once it starts, it gets to polar bear cycle fairly quick, which I will appreciate immensely come August!
 
This just happened to me. I got in ,turned on the air
and it was blowing cold air. Drove maybe a half mile and
had to stop for construction.It was stop and go for 1
mile and the whole time it was blowing hot air. Once
traffic started moving steady it returned to cold. I thought it was a hickup but maybe there is a problem.
 
This sounds like a control, thermostat and/or a fan clutch problem - I think you have a valid issue for a dealer to work on - this is not the norm ;D
 
Ditto: Same here. Started the truck, got it cranked up, got stopped in traffic and it got hot. As soon as I started moving, it chilled back down.
 
Well, it's just about getting hot enough here in Colorado to give this experiment a try.

Sure sounds like something's cutting out the compressor at idle - though I can't imagine why. Now, the cooling capacity drops considerably at idle as compared to higher engine RPM's, but the difference described here seems more drastic than this.
 
I turn on the A/C yesterday in park and it was blowing only hot air at first. Speed the engine up a little and it started cooling fine. let off the gas and it would start to warm up again.

If all you get is hot air while driving it, stop and check to see if the A/C compressor is running and check to see if the suction line (the larger one ) going to the Coil box on the firewall is sweating. The large canister called the accumlator should be sweating also. If these items are working and all you get is hot air, it is more than likely the damper motor not working.

This was the problem I had with a 99 1/2ton Silverado.
 
Never had a problem while driving, only when in Park.

I think gandolphxx is on to something, it's got to be a thermostat problem because it only happens on hot days.

Gotta get it fixed because it does get HOT down here in Texas in the summer!!!!!!
 
I have the same problem. Has anyone talked to the dealer about this yet? It will be awhile before I can get to the dealer. Let us know what you find out.
 
Falcon,

Look 20 threads down about GM Techline link. I printed the bulletin right off the thread and gave it to the dealer.

Had it at the dealer Monday so still early to tell if they fixed the problem or not.

But I do have a little rattle from the dash hitting the windshield now which I didn't have before.

Isn't it normal to take a problem to a dealer and it takes 2-3 to get the orginal problem fixed plus everthing else they messed up?
 
I recently got my AVA back from the dealer for AC work I had a leaky valve and after they fixed it I picked it up the AC just blew hot air. I immediately took it back and they checked it out and said that it ws a faulty fan clutch. They repalced it and voila problem solved. ;D
 
Just_Bruce,

Forgive my mechanical ignorance. I've never had a problem with the AV blowing cold air as the car was moving, just when idling after start up.

Does the fan clutch affect this problem?
 
Leather said:
It snowed here again Yesterday :6:...need some heat here in Alberta....
Click to expand...
Funny you should say that... I would be very happy with about 6" of snow right now. :cool: :cool: :cool:
It seems like our winters get shorter every year. When I was in elementary school we were snowed out of school at least once or twice every year. That doesn't happen anymore.
If you're itchin' for a roadtrip, load up the rig with some of those flakes and head on down to "Big D". ;D ;D ;D

helmet
 
Dandan, the condenser is in front of your radiator. If you are not traveling then no air is blowing through it. If the fan clutch is not engaging then it wont suck any air to cool off the condensor. I am not a mechanic but that is how they explined it to me and logically it makes sense.
 
Well, I took her in to get the A/C fixed (with TSB in hand). They siad they fixed things but............. no.

Sunday was warm, started car, let idle for a couple minutes, drove slowly through a state park but didn't start cooling until I got going (30+mph).

If warm (or certainly not cool) air is blowing through the vents, would that not be a fan clutch problem or is there something in the dash itself, like a sensor?

(I don't have climate control)
 
DanDan,

I've recently had a simialr problem...goes away as soon as I start driving though. It's only happened twice to me so far, but I'm in C. Texas too and know how hot it has been lately.

Did they ever fix anything on yours??

Jeff in Austin
 
Don't know if the A/C is at all similar (doubt it), but same thing happens in my '95 S-10...blows hot air until I start moving. As you all noted, this only happens when it is hot out (90+).

I can't even come up with an off-the-wall theory about this one.
 
Just read this in the owner mannual not sure if it only applies to Av's with the electronic climate control system.

Section 3 Page 4.

If the air conditioning system is activated and system
demand is high in situations such as city traffic, idling,
or very hot weather, the system will automatically
switch from outside air to recirculation. The LED
indicator will not change. After demand on the system is
not so great, the system will return to outside air.

Is it possible that the air tempurature in the cab is still resonably hot causing hot air to be blown?

z-man
 
Mine did this at lunch today. Fan speed changed, and temerature of air changed until I got moving. Only had the AV for a week so I wasn't sure if it was normal or not. Read the same blurb in the owners manual. I don't have climate control.

If it's normal, i can live with it... Other than the radio or speakers I love mine

 
I think this situation is normal if your AV has been baking in the sun for a few hours. :0: If I pull either my AV or Tahoe out of the garage and turn on the A/C it is cool almost instantly. :cool: even if it is 95 degrees out and 100% humidity. If I turn on the A/C after the vehicle has been sitting in the sun while I'm at work, it takes a mile or two before you can appreciate the effects of the cool air. It really makes sense that the A/C would take a few minutes to kick in considering it has been heat soaking :sleep:and you need to pick up the engine rpm to start the A/C working effeciently. :p
Truckman :B:
 
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