A/C Problems

T_B_TEXAS · May 23, 2006

Has anyone seen a problem with the A/C, where when you start the truck it is blowing cool air, but if you stop at a light or drive thru, the A/C will start blowing what I call vent instead of a/c air. It seems to go away as you start driving or in nuetral reving the rpm's above 2000. I know when it is hot outside and the truck is at idle, the A/C will not blow as cool air as if you were driving, but this is actually warm-hot air at idle. I did a search and found a few topics, but none just like my problem. Any help wold be appreciated.

2001 GMC 2500HD

56,000 miles

blk99SLT · May 23, 2006

Has anyone seen a problem with the A/C, where when you start the truck it is blowing cool air, but if you stop at a light or drive thru, the A/C will start blowing what I call vent instead of a/c air. It seems to go away as you start driving or in nuetral reving the rpm's above 2000. I know when it is hot outside and the truck is at idle, the A/C will not blow as cool air as if you were driving, but this is actually warm-hot air at idle. I did a search and found a few topics, but none just like my problem. Any help wold be appreciated.

2001 GMC 2500HD

56,000 miles

<{POST_SNAPBACK}>

Check your condenser (in front of radiator). Make sure it isn't blocked with debris.

dewfpo · May 25, 2006

Check you fan clutch and make sure it is pulling allot of air at hot idle.

DEWFPO

snoman · May 26, 2006

It could also be a weak/worn compressor that has a lot of internal leakage at low RPM and does not flow much refridgerant through system during those times or build up much pressure.. The best thing to do here to trouble shoot it is to put a set of gauges on it and see what the pressures are at a idles and it will give you a lot more insite as to what is really going on instead just guessing.

sxmax · May 26, 2006

Your fan is not drawing enough air through the a/c coil at idle. They have a bulletin out on this where you install an additional electric fan that runs only when A/C is on. I had to do this in order to keep my A/C cold on my Yukon Xl with the 8.1 at idle.. I took the fan assy and wiring harness off when I traded the Yukon. It is just collecting dust if it is something someone is interested in, I will give someone a deal. I probably can get my hands on the bulletin as well.

dewfpo · May 26, 2006

sxmax,

If it's possible for you to post the bulletin, it would be appreciated.

DEWFPO

taco · May 26, 2006

SXMAX

I sure would like to see that bulletin myself - Thanks

snoman · May 26, 2006

SXMAX

I sure would like to see that bulletin myself - Thanks

<{POST_SNAPBACK}>

I have all bullitins through June 2005 and there is no such animal for that year/model. There is one for A/C odor

sxmax · May 30, 2006

It is listed for multiple models one being the escalde with 6.0ltr, but it has been a few years. I will stop down at lunch at the dealer and have them pull it for me again.

icecoldtexan · June 4, 2006

Has anyone seen a problem with the A/C, where when you start the truck it is blowing cool air, but if you stop at a light or drive thru, the A/C will start blowing what I call vent instead of a/c air. It seems to go away as you start driving or in nuetral reving the rpm's above 2000. I know when it is hot outside and the truck is at idle, the A/C will not blow as cool air as if you were driving, but this is actually warm-hot air at idle. I did a search and found a few topics, but none just like my problem. Any help wold be appreciated.

2001 GMC 2500HD

56,000 miles

<{POST_SNAPBACK}>

My 2001 2500HD does the same thing, not every time, but sometimes it will act like the compressor doesnt come on. My 2005 2500 Chevy work van does the same thing sometimes.....must just be "normal a/c operation" reminds me of the "normal" engine knock !!

jake111 · June 4, 2006

I'm sure it's just me . . . and I'm imagining things . . .

I have the automatic dual-zone control and even though I run it in manual, it has a mind of it's own (I guess it thinks it knows better). Sometimes the a/c icon is lit up but the air coming from the vents doesn't seem cold. I turn it off, wait a few seconds, turn it on, and I get cold air and everything is ok after that.

It also turns on recirculation when it feels like it. I know, I know, it knows better than me, but I wish at least the manual mode would humor me.

dewfpo · June 4, 2006

Yeah, I've got the dual zone auto climate control and I don't really care for it. I'd rather have the old manual system. At least you know what you asked for. These automatic systems do what they want. They think they are smarter than the driver. I know in some cases they are. But.... I drive on allot of dusty dirt roads and I push the recirc. button to try not to suck in all the dust. The light comes on, then sometimes it goes off on its own, especially if I don't have the A/C on as well. It's frustrating.

DEWFPO