Lackluster A/C performance

FIRECAT · June 27, 2003

Just got my new '03 2500HD crew cab, Dmax/allison this week, as we get hit with a heat wave here in the Northeast. Been about 95 deg. and humid all week. The A/C in this truck takes forever to cool the cab. I just doesn't seem to be blowing cold air. BTW: it has auto climate control.

Any ideas? Anybody have the same problem? I am going to take the truck to the dealer and see if they can maybe check the charge on the refridgerant system???

Thanks

1BADHD · June 27, 2003

If the truck has been closed up, it takes a litle bit. But mine cools it off pretty good. Leave it on and you'll have frost on the windows!

FIRECAT · June 27, 2003

If the truck has been closed up, it takes a litle bit. But mine cools it off pretty good. Leave it on and you'll have frost on the windows!

That is exactly what my '00 1500 would do, this is not even close to that. Takes a good 20 minutes to cool down, and even then its not that cold.

clk7711 · June 27, 2003

My parents own an 03 Duramax that has been in the shop twice already for the A/C. First time they replaced the compressor cycling switch and that fixed it for about 4 days and then it stopped working again. The second time they recharged the unit and that was a couple of weeks ago. I drove it the other day and still doesn't seem right. Not as cold as my truck thats 4 years old.

I know of one other person who has been having trouble with his A/C in his Duramax also.

He has the auto control and my parents have the manual. It doesn't seem to matter.

I'm in South Texas and its real HOT!

1BADHD · June 27, 2003

I know you shouldnt have to do this on a new truck. But have you considered a electric fan that pulls insame amounts of air? They say you should pull 4500+ cfms. I know a stocker cant do that. I am not sure if you could even do that on a Duramax.

Shaners · June 27, 2003

I crack open the windows in my truck, and it seems to help cool the truck down faster. I think that allows the cool air to move more freely through the vents.

I've noticed that if the truck is left at idle, the A/C is not as cold as it is when the truck is running down the road.

TPN · June 27, 2003

Firecat, have you tried the a/c with the recirculation selector button pushed in . . . . . that makes a pretty significant difference for me . . . . . recirculates the inside air, as opposed to the hot humid outside air . . . . . seems to cool off a lot quicker!!!

FIRECAT · June 27, 2003

Firecat, have you tried the a/c with the recirculation selector button pushed in . . . . . that makes a pretty significant difference for me . . . . . recirculates the inside air, as opposed to the hot humid outside air . . . . . seems to cool off a lot quicker!!!

Yup, tried that, it definately helps, just doesn't seem right.

Thanks for the replies.

grndually · June 27, 2003

Yeah, had to do that also. It works much better that way in the 95 degree heat we had yesterday and today.

Off topic: Firecat, what make are your 2500HD 8100 crewcab running boards and where did you get them if I may ask? Thanks!

Good luck, Andy

Moonlight · June 28, 2003

I also have a new 03 Duramax CC ... the A/C on these trucks seems to be a common problem/complaint. It's a popular discussion at the moment on thedieselpage.com. I too think the A/C performance is sub-par. Guess it's a good thing live in Oregon where I don't use it very often.

sonjaab · June 28, 2003

BLAME those darn treehuggers and that new R-134

stuff. The A/C on my Caddy and truck work OK here

in NY. But if I lived down south or out west it would

be terrible.

My 94 Yukon with the R-12 would blow snow !

Good thing I bought 6 -30 lb. cans of it for $79 bucks

each a few years back. Gotta keep all my a/c units, compressors, ice cream machines, and ice machines running as long as possible! Man that stuff is like $700 a can now.

Its funny its manufacture is outlawed here in US and

Canada. But those chemical companies are still making

it in mexico and its a big business smuggling it back to the US. Go figure.

BTW: I have a couple new R-134 setups and they don't

cool the beer worth shucks either!.............geo

lrymal · June 28, 2003

Firecat, have you tried the a/c with the recirculation selector button pushed in . . . . . that makes a pretty significant difference for me . . . . . recirculates the inside air, as opposed to the hot humid outside air . . . . . seems to cool off a lot quicker!!!

For nearly twenty years, from the 60s to the 80s, that option used to be called "Maximum Air". Ever since I was a kid, we always had to use MAX down here in the Houston area.

Today is no different. My truck literally freezes me out in this hot summer and steamy air but while I'm using "Max" air, or "recirculate".

422 SS · June 28, 2003

My 2003 Dmax has ice cold a/c.If I'm running down the freeway I cant set it past the second setting or it freezes me out.

jbplock · June 29, 2003

(First Post here). My 2003 2500HD D/A CC SB is also having the same A/C problems. It works fine untill the outside temp hits the 90's. With the recirculate on, it takes a lonnn..gg time to cool just a little. It's better than nothing but not much. Seems to be a common complaint. Guess I'll have to make a trip to the Dealer.

jbplock · June 29, 2003

I looked in my 2003 GM (Helms) service manual and there is a performance test on page 1-9 (Vol–1) that measures the operating efficiency of the A/C system under the following conditions:

Truck parked inside or in the shade.

Ambient Temp & Humidity

High & Low side pressures

Outlet air temp discharged in the cab.

The procedure says to record ambient temp and humidity and check the static pressures (engine off). Next start engine and run the A/C on Max for 5 minutes with re-circulate on and driver’s window open 5-6 inches Record High/Low side pressure and cab discharge temps. With this data you look in a table to see if the system is “normal”. For each range of ambient temp and humidity the table lists a range of High/Low side pressures and Maximum discharge temp.

Here are a few excerpts from table.

Ambient air temp 76-85F, below 35% RH: Max Discharge Temp 63F

Ambient air temp 76-85F, 35-60 % RH: Max Discharge Temp 66F

Ambient air temp 76-85F, Above 60% RH: Max Discharge Temp 68F

Ambient air temp 86-95F, below 30% RH: Max Discharge Temp 79F

Ambient air temp 86-95F, 30-50 % RH: Max Discharge Temp 72F

Ambient air temp 86-95F, Above 50% RH: Max Discharge Temp 75F

Ambient air temp 96-105F, below 20% RH: Max Discharge Temp 81F

Ambient air temp 96-105F, 20-40 % RH: Max Discharge Temp 84F

Ambient air temp 96-105F, Above 40% RH: Max Discharge Temp 84F

This seems OUTRAGEOS to me! A very UNDER-DESIGNED system! I not an expert but I have repaired and recharged a few auto A/C systems over the years and I have been able to get discharge air in the 40’s and 50’s (with R12).

I have been waiting for an excuse to upgrade my A/C gauges and fittings for R-134A, so I guess this is it. I’m going to run some tests but I would guess my truck would pass the criteria in the table with a “no-trouble-found” if I took it to the dealer.

Anyone have any further insight into this? From some of the other posts, it seems like some systems work much better than the spec in the service manual.