First time poster. I've read through a number of articles on this site about various problems with the 3rd gen A/C system, but I'm kind of lost.

A couple of weeks ago, when we started hitting 100 here in the Central Valley, I noticed that my A/C was blowing warm on the passenger vents, but cold on the driver side. I tried the Heater Treater suggestion for testing whether it was the blend doors -- clamping off the heater hoses coming in through the firewall -- but it did not change anything. However, I then tried using the A/C through the defroster vents, and that seems to work fine on both the driver and passenger sides. That makes me think perhaps it's not the blend doors. I tried topping off my refrigerant, which didn't fix the problem either (although I have not yet, as Heater Treater also offers as a solution, charting the various pressures and up/down-charging to see if the problem is corrected at a different pressure).

Any suggestions on diagnosing? I started to take the dash out, but my problem is I need the truck on a pretty regular basis, and I can't have it down for more than a couple of days.

 

Lol. Turns out I just wasn't recharging the system enough. I also had a bad condenser fan, so after I replaced that today, I gave the recharge another go before committing myself to a bigger teardown, and lo, once it got to 35-40 psi, the passenger side started blowing cold too. So it seems I may just have a leak somewhere that needs finding.

(If you're doing the recharge yourself, watch out for a YouTube video that shows a guy using the high pressure port to do the recharge, instead of the low pressure one.)