Air Conditioning Blow Hot Air

[Diesel Crat]

Did a search and only found 2 forums remotely close to the symtoms being experienced. I know this is the 6600 page but more folks check here than the gasser page.

I traded my 01 6.0 gasser to my brother for the 02 6.6 I have now (Don't ask why, he asked me do it and I gladly agreed). Anyway, I remember having intermittent problems with the Air Conditioning blowing hot air. After Engine on/off cycle and fan switch on/off cycle it usually reset and everything was OK. Brother says its doing it again. I remember having the dealer take a look at it when I owned it but they found nothing.

The other forum topics I found talked about the A/C pressure switch failing and cycle switch failing. Are these the same thing and are they the problem or does anyone know of a TSB or had a similar problem?

[madmatt]

yeah there's both a low pressure and high pressure cycling switch. Most of the a/c problems have been w/ the low pressure switch and there is a bulletin out on how to properly diagnois it. the bulletin # is: #04-01-38-010.

[Diesel Crat]

Thanks for the help. :D smile.gif :cool:

[Nix]

I had a similar problem on my '01 and as it turns out there was a wiring harness with a plug that wasn't seated all the way. It was the one right on top of the compressor. It didn't separate completely until I tugged on it a little to check. Pushed it together until it clicked, and Voila! AC restored, cursing stopped and no trip to the stealer required!

[Ranger354]

My DMax did the same thing twice in one day. I turned it off each time and let it set. then turn the ignition slow and let the glow plug light go out each time. Worked fine both times afterwards. This was back in November and it hasn't happened again since. Go figure. Also had the Service 4x4 come on. Did the same thing and all codes cleared and have never had any more trouble with it.

[C. Babb]

not sure if you have gotten the problem fixed, but a friend of mine in his 2001 vette z06 had the driver's side blowing out hot air and the passenger side blowing out cold air (mid. of dec.) and come to find out he took it back to the dealer with a list of problems and there was a short in his ac/heat unit

[57CHEV]

Could you be low on freon? The low pressure switch sounds like it's working or the compressor would not come on at all. Just a thought.

[More Power]

There's a new article that'll be officially announced on the 15th that discusses the A/C system. Some of the info here might be of some help.

Have a look! (http://www.thedieselpage.com/features/airconditioning.htm) smile.gif

MP

[J T]

Had a similar problem with my 01 DMX. I thought it was the low pressure/ low freon levels, but that wasnt it. I would periodicaly only get warm air from the A/C, and a full battery disconect was the only way to reset it.

Finally, my lower left circulation light went out, and after my dealer looked at it the fix was:

A whole new freakin control unit! Yes, the master unit with all the dials and buttons. Just replaced it (dealer charged 300, but was under my extended warrenty) and now my A/C is cold as hell, and everything works schweet.
Interestingly, buttons on my climate unit had never worked properly, like choosing the type of circulation you want when the fan is off, I can do this now! YAY!!!!!!!

[lovette]

saw on another forum a TSB regarding accumulator replacement