A/C and heater problems

[Krch0210]

i have owned this 05 Tahoe Z71 for just about 2 years now. I am having very strange problems with the A/C and heat. When working it is amazing. The first time this occurred was about 1 year ago. All of a sudden nothing would blow out - heat or AC. I read a few threads and everyone said to replace the Resistor. Which I did and everything worked for a few months. The issue came back this past winter so I purchased another resistor. Again, this fixed the issue but it stopped working again a few months later. So, I purchased a new blower motor and another resistor. Again, it worked for about a month and just stopped working yesterday.

Does anyone have any suggestions? Or has this happened with anyone before?

 

[Tahoe0159]

Are you buying OEM resistors or some cheap brand (like from Autozone)?

I've had Dorman resistors blow (in other cars) several times (in other cars) and finally went an bought OEM from the dealer. Fixed the problem.

Usually that resistor blowing over and over is an indication of the blower motor pulling too much current, but you said you replaced it too.

Anyway, I would try an OEM one and see if it is any better.

 

[TwiztidXL]

I would also recommend replacing the harness. A lot of the gm resistors will heat up and burn on 1 or more of the pins which in turn can damage the harness. But I would definitely get an OE resistor instead of a Dorman, This coming from someone that sold dorman resistors for nearly 12 years.

 

[Krch0210]

Here is what I purchased from www.rockauto.com

Four Seasons Part # 20340
Front; w/ Automatic Temperature Control

It obviously doesn't have OEM listed anywhere. This party is sold for $83.79 (believe it is actually more at Advance Auto/Auto Zone).

Rock Auto is also offering the following (which I haven't purchased):

ACDELCO Part # 1581773 (Click info link for Alternate/OEM part numbers) GM Original Equipment (one of the most popular parts)
A/C FRT AUTO/AUX CONT (CJ2)
This part is only $50.89.

Are you guys saying I should go with the ACDELCO? As an FYI, each time I have put in a new resistor I have changed the wiring harness.

Is it possible that it could be the actual main CONTROL UNIT in the dashboard? Since mine has the AUTO option and digital screen I have noticed that sometimes it does get pretty warm on the main screen.

Let me know your thoughts.