Ok I've been trying to figure this out over the last week and I'm stumped, my ac just stopped working. I use it everyday to work and one day I got in and just blew hot air, thought I had a leak. Then I drove it early morning tried the heater just blew cold air, now I realized it's just blowing outside air into the cab.
I just went out and tried checking a few things and I don't see anything broken or wrong. So I tried switching from hot to cold and listen to see if I can hear it switching and I do not. The temp does not change from hot to cold exact same temp, anyone had this issue? I figured I'd ask before I start ripping it apart.
thanks.

 

I found a post I was looking for and I seen the motor getting stuck heater is now working but the ac is not. It was blowing cold one day and the next it just stopped blowing cold.

 

Let me tell you what I tested, ac clutch does kick on, fan kicks on and it is only blowing the outside temp air. Here's a video of what I hear turning the ac on and off:
https://photos.app.goo.gl/1xa21erjz6vYYaBk9

 

1. Have you verified the blend doors are working? Look under the dash and switch from max HI to max cold. You should see the actuators move. If this is working you might have a slow leak, where there is enough freon to set of the A/C Clutch but not perform well.

 

Yes, that is your likely culprit. I removed the drivers blend door before and cleaned it up, but the next time it failed, and now I just manually moved it to stay warm all the time, got me through the winter. One of these days, maybe I'll pull it and replace it, or try and clean it up again. I would be surprised if your a/c continued to work much longer on an older model, they fail quite regularly, and usually need a new clutch actuator. Wasn't worth it to me to go through the work on an old car, in my climate, heat in the winter is more important.