Heat and Air problem...

[Bcox]

I have a 2003 z71. My problem exists with both air conditioning and heat. I hope I can explain it to where it makes sense....

As i'm driving the heat/air (depending on winter or summer) will be fine, then it just cuts off. Still blows a little but not at the setting its set on. If I turn it off completely and wait a couple minutes and turn it back on it works again. I have had the blower motor replaced and that didn't fix the problem. Mine has the digital AC/Heat climate control on the dash. No one seems to know what the problem is. Someone said heating core, but it happens with both the AC and heat. It will just stop working but still kind of blow, I will turn the system off, wait a couple minutes then turn it back on and it works again. I just repeat the process....Anyone know whats up?

 

[swathdiver]

I had this exact problem on another GM platform, drove me crazy. Know what it was? Low refrigerant! Damdest thing!

 

[Bcox]

So the low refrigerant can make it cut on and off? Were you able to add refrigerant yourself?

 

[Bcox]

Also would the refrigerant cause the heat to do the same thing? Cut in and out?

 

[Doubeleive]

I had the same problem on my 03 Silverado with the digital control unit, it needed Freon for the a/c and then I had to replace the digital control unit, only difference is mine would not blow cold air I would have to shut it off wait a minute and then turn it back on to get cold otherwise it would blow warm, but even after filling the Freon back up it still did it, replaced the control and problem is gone. it seems to be a common issue for the digital control, dorman has them-remanufactured for better than oem price. I would check the rockauto website for best price and there is a sticky on the forum for 5% off.

 

[Doubeleive]

if you want to add Freon to check that first you can buy the can's with trigger top/gauge and hose at most autoparts stores, they charge extra for the trigger top with gauge but you will have it for next time it just unscrews off the can

 

[Bcox]

Thank you for the reply!!!! When I have the AC on it blows cold, very cold. Just cuts in and out so I have to turn off the power, wait a few min and turn it back on. So if I'm correct in what your saying, I need to replace the control unit?

 

[Doubeleive]

Thank you for the reply!!!! When I have the AC on it blows cold, very cold. Just cuts in and out so I have to turn off the power, wait a few min and turn it back on. So if I'm correct in what your saying, I need to replace the control unit?

if the Freon is full then yes that would be my next suspect, they run around $120 or so, there is 2 different ones (I think) depending on your options in the truck
it's pretty easy to take out and look for a part number on the back, it will be a old part number but should crossover to a more current number, dealer can tell you for sure with the vin.

 

[Bcox]

gotcha. on rock auto website it shows an Acdelco unit for $118 and a Dorman unit for $150... Would you recommend the Dorman over ACdelco?