I am working my way down the list of troubleshooting. I finally have all the interior electricals tracked down and working, replaced bulbs, connected broken connections, etc. Tomorrow, I install the stereo I got for Christmas, finally.
I'm going to get the AC charged tomorrow morning, next item on the list.
On another forum, Fullsizechevy.com, I ran across an interesting thread on cleaning out the core in the cab section, inside the box near the fan motor, underneath the ECM. I'm going to check it out because I have the dashboard dismantled down to the two rivets behind the instrument cluster. I'm used to drilling those out like in my vintage Airstream interior skins, also troubleshooting electrical issues. Fun with rivets, another chapter in my book of projects.
Here's the link to the AC core idea. Those guys said it makes a big difference if your AC isn't cooling like it should, or the velocity of the fan seems lower than it should be.
http://www.fullsizechevy.com/showthr...ght=dash+paint
But the point I started out with is this: When I turn on the AC control, a sound begins, like the sound of an oil can popping, on and off, with corresponding "revving" of the engine, up and down as the metallic popping sound goes on and off. Yet, I feel no cold air coming through the vents. That's why I'm going to get the AC charged up (it will be free, so worth a try). Then, I'll try the cleanup of the core.
BUT -- maybe there is something else going on?