Chuck!

OK, finally the AC works. Stock HVAC controls and 04 CTSv compressor, pressure sensor. This is with a 12586243 PCM, which is stock in a ton of cars/trucks/vans running a 04 CTSv OS tune.

The V pressure sensor is female, where as the fbody is male. I went to a yard and got the liquid line off a 2003 CTS, which runs the same pressure sensor, and had the shop that did my AC lines splice the CTS sensor onto the stock 91 liquid line.

Here's how I have it all wired and tuned:

Wiring - AC request
Jump 12v off green/white from back of HVAC to PCM green 17

Wiring - fans (single fan car):
Run both low (PCM blue 42) and high (PCM green 33) outputs to the same terminal on fan relay (85)

Wiring - pressure sensor:
PCM Green 14 to AC pressure sensor - pressure sensor signal
PCM Blue 45 to AC pressure sensor - 5v ref
PCM Green 57 to AC pressure sensor - low ref

Wiring - AC relay:
85 - ground from PCM green 43 (this ground activates when AC is requested and the sensor is within normal pressure)
87 - signal to ac compressor
86 & 30 - hot with ign
Hybrid from Pocket's posts 13 and 21 in this thread: https://www.thirdgen.org/forums/ltx-...ng-i-need.html
-For the blue/green PCMs, you do not need to run a wire out of green 18, as you have to with red/blue PCMs

Correct settings in tune (via HPTuners), this seems to be the hardest part to find:
System -> Fans
AC Fans disable speed: 65 (this keeps fan on up to 65 mph)
System -> A/C
Recirc option: Fan 2 (this turns PCM green 33 into a ground when AC is requested)
AC Type Fitted: Analog (stock on most blue/green PCM cars is serial since there's a BCM, but stock for vans with this PCM and no BCM is analog)

The posts in this thread from 'G-Body' were awesome for learning PCM settings:
http://ls1tech.com/forums/conversion...tor-ecu-2.html

The last thing to tie it all together was getting the fans and AC to work together, this thread was the last piece of info I needed:
http://www.performancetrucks.net/for...needed-539577/

Hope this saves someone headaches in the future. Even if you're not planning on running AC from day 1, I'd get the settings tuned when you get your VATS, etc changed. No harm in it.

Thanks
Chuck