2004, D/A CC 2500HD...approx 4300, owned it less than a month.





Problem:


Since i first got it the end of June, the AC has not cooled as it should (same complaint as everyone). Today it cooled first thing this AM, but the second time i got in the truck, around 10AM, it will not get cool, not matter which setting you select.


I checked all of the associated fuses, (except for the grey "module" under the hood, in the black fuse box). I then started the truck and turned on the AC, the AC compressor is not kicking on....


Any help? its HOT in Florida!!


WhenI called the local stealer, which i refused to buy from, the service man asked me when i would like to bring it in....I said "sir, as soon as possible." He replied, "well how about sometime next week?" I said "sir, it's July in Florida, that's as soon as you can???" ..."no, you can bring it in on thursday, do you prefer AM or PM?"....


What part of ASAP did he not understand???http://www.dieselplace.com/forum/smileys/Angry.gif

Do you have climate control?? My truck has manual climate control and the couple times that ive decided to use mine, it doesnt seemed to really cool, then itll take right off for a little bit then stop. I just assumed this was how it was suppose to be, but maybe since so many folk seem to be bringing up quite a few different AC problems, ill have mine checked when it goes in late aug
Also the fan settings on mine seem right next to useless, as 1-3 seem to not change at all then 4 and 5 will blow you out of the seat...http://dieselplace.com/forum/smileys/Ermm.gif

It sounds like the low pressure switch might be the culprit. Who is the dealer?

I bought it at Griner Chevrolet in Quitman GA...The local stealer is Tommy Thomas in Panama City...





Would that cause the Compressor not to engage??

I had a similiar problem with the A/C not cooling well. On mine, the compressor will cycle even though the vent temp was around 70 degrees. My first thought was either low freon or the low pressure switch. Sometimes the A/C will cool okay at idle but at above idle, the vent temp will start to rise. Took it back to the dealer; they change out one Schrader valve core and recharge the system. It cooling down to 50 degrees. Not cold enough yet but better than the 70 degrees before hand. You might want to check out the TSB forum. I hear about the accumulators being incorrectly sized for the 2004 DMaxs.

Here is a thought. I had a simular problem with my 89 burb and it turned out to be air leaking through heater core (which is always hot in a GM truck) and GM's TSB was to have water flow shut off when A/C was selected with a added valve (still flows in defrost though) and it cured problem. Try temporarily clamping off one of the heater hoses and see if cooling performance is improved. Also, a improperly sized accumulator would effect cycling of compressor but would have little effect on actual cooling capacity. Edited by: snoman

UPDATE...


Got in the truck this morning, started it, AC came on blowing cold air...Should I still take it in????


I think Onstar must have sensed how hot i was, located my truck through the satellite tacking device, remotely unlocked my doors, and sent a service tech out last night to repair it while I slept...Got to love Onstar...http://www.dieselplace.com/forum/smileys/Big Smile.gif

If your compressor did not come on you may have a bad low pressure switch Gm had a problem with some for a while. My last gas truck would do that, it would work for a while then stop and the next time I started it it worked fine. Take it in and have it checked.

Next time it does not come on, raise the hood and use a paper clib to jumper past switch on accumulator and see if it engages and runs as there is also a hi pressure switch that can be bad too.

my a c works fine at idle trough 35mph very cold.about 5o mph it starts blowing warm. back off some and it colder then hell. what do you think

I think it's just stupid that the gassers work and ours don't....... just plain crazy.


...... yeah, that's the one one I want. Yeah, the 40k truck with bad AC. Sure don't want these folks to think I'm high folut'n, you know .... having working AC in my pickup.


I know we would find something to complain about if the AC did work.......... but man, it's freak'n hot!

the gassers have a different compressor than the diesels...the dieseld employ a jap compressor..however, my servicing dealer will be installing a newly upgraded accumulator as soon as i t arrives..will keep ya posted.

Bob, that's what I'm talking about. I have never been in a Toyota that did not have freak'n COLD AC... never. Actually, I've never been in a Japaneese car that did not have really cold AC. Why would our trucks have crappy AC with a Jap pump?

I think it's just stupid that the gassers work and ours don't....... just plain crazy.


...... yeah, that's the one one I want. Yeah, the 40k truck with bad AC. Sure don't want these folks to think I'm high folut'n, you know .... having working AC in my pickup.


I know we would find something to complain about if the AC did work.......... but man, it's freak'n hot!

I am thinking that as you get up to speed in a diesel that there is not enough good airflow through radiator assemnbly due to higher air flow resistance cause by condensor, intercooler, thick radiator and tight engine compartment when fan disengages vs a gasser. At lower speeds the fan may stay "in" and cool freon better in condensor and yeild better cooling. I think maybe the GM needs to rethink the clutch fan specs and calibration on Dmax trucks.

Good asumption Snowman. However, I have been in several GM 6.6 trucks that have cold AC, not blistering but very cold AC. I wonder how the Ford and Dodge trucks just "sit" for hours in the direct sun and freeze the bejeesist out of you?

Good asumption Snowman. However, I have been in several GM 6.6 trucks that have cold AC, not blistering but very cold AC. I wonder how the Ford and Dodge trucks just "sit" for hours in the direct sun and freeze the bejeesist out of you?

If my theory is true, it would not take much extra fan clutching to make it happen. On the Dodges and Fords they may use more agreesive fan clutching to begin with. The clutch fan on my K3500 gasser is very agressive and has a 10 bladed fan and A/C always works quite well even in traffic and engine temps stay stable at all times and it is not really noisy either. I have tweaked the Bimetal coil on the clutch fan on my burg on occasion and a tiny bit goes a long way (less than 1/16" can make a big difference) so production tolerances could account for why some GM's Dmaxs cool pretty good and some do not.

http://www.dieselplace.com/forum/uploads/cool_vent_temp_010_33.8_comp.jpgBelieve it or not, my AC seems to work OK. No I did not put the thermometer in ice! 88 degrees outside, fan speed 2 (1 is burned out), recirc, truck sitting for 1/2 hour at idle. Going down the road vent temp is between 38 and 42 degrees. Edited by: Dr Crane

THats not bad but the real test of a A/C is not on recirculate but on normal. In the old R-12 days you get cold air in the 40's with it in the 90's outside in normal mode with water just pouring out of the evaporater drip tube. I have never gauged my 2000 K3500 but it is quite cool all the time and I never use recirculate on it either.

It is not a problem with all Duramaxes, which means it can fixed. Mine will cool down the cab to point of it being uncomfortable when it's 100+ deg outside.

While it is doing so can you also here the clutch fan more actively involved? (I am not picking on Dmax's, just trying to find the common problem)