2005 Sienna XLE only blowing hot air while AC is on

madmanmoose

I have a 2005 Toyota Sienna XLE AWD. Yesterday (while it was 101F) the AC suddenly stopped blowing cold air. The 'Auto' setting worked, showing that it was on 'LOW' with the fan on high. When on 'Sync', front and back fans were all blowing. BUT...it was only hot, humid air coming out. I verified that the anti-freeze levels were fine, so it isn't that. After I reached my destination, I turned the AC on and off...and, didn't hear the compressor kicking in...so, I'm pretty sure that the clutch wasn't engaging.

I have a good mechanic (the local Toyota dealership's service center is a rip-off), but, would still like to get a handle on what the root cause is before I hand it over and incur expense.

Any suggestions would be greatly appreciated!