I own a 2005 Chevrolet Tahoe with 54,000 miles and dual climate control. I got into it today and cranked up the AC and got nothing but hot air. I started and re-started at least 10 times and still hot air. A few other interesting things have been going on with it too and not sure if they could be related but I will list in case they are helpful and PRAY someone has the answer.

A few weeks ago, my aftermarket alarm system started acting up and would give me that chirp that tells you there is a door open or something when you set it. I checked all the doors and they were closed but it intermittenly would do this. I changed battery in remote and it seemed to be a little better, but has begun to do the same thing again.

Within the last 3 days, I have noticed that it takes a little bit longer for my truck to start. In other words, it turns over ok but seems to take a little longer to start. I plan on replacing the battery as soon as I get a chance. I am thinking that the alarm going off so much could have drained the battery. Plus I live in Phoenix and living here KILLS BATTERIES FAST.

So my question is: Could having a battery that is going dead make my AC only blow hot air? Should I replace the battery first just in case? Anyone else have this problem?

BTW: I am out of my factory warranty but thank god bought an extended warranty. Unfortunately, it has a $100 deductible and I would rather use that towards a new battery if that is all it is.

 

I think your on the right track about the battery, if its more then 3 years old and in that heat, its probably going and a "funky" start or an alarm chipping is usally a good first and maybe only sign until it leaves you stranded.
For the A/C check and make sure the compressor is even coming on, if the clutch is not engaging it will never get cold, if its not engaged check to see if you are getting voltage, then check the fuse and relay... a leak is progressive and you will notice it getting warmer over time, not getting cold at all is an issue of not working.
That said if you have the rear A/C check under the truck and make sure there is no damage to the A/C lines running to the rear unit, those are the most exposed and most likely to be damaged.

 

Can get battery and alternator checked for free and Advance Auto and other auto parts stores. Good luck. No A/C in that area is not for the faint hearted.