A note, on anyone who ever considered doing a single zone manual AC to dual zone climate control conversion.
It is possible, it can be done. I just pulled it off in my SS.
Get the factory workshop manual or some other guide that tells you how to pull the dash out because that's how deep into the car you'll have to go.
I got all the required sensors as chinese knockoffs, they work fine. You need the dual zone spec sun sensor, interior cabin ambient and exterior ambient temp sensors. Get the exterior one with a pigtail if you can otherwise trying to weatherproof that connection will be ****. I got myself the whole heater box out of a dead car so I had some spare wiring and plugs and a dual zone HCM, this comes in handy below. Also get another HVAC actuator.
For the internal sensors, if you're doing this swap, your car will not have the required wiring or plugs. I used a small auto-style figure8 cable from jaycar, and some small crimp on spade lugs (telephone style) with heatshrink to get onto the pins of the interior sensors directly.
THIS DOCUMENT
http://adair.com.au/tsb/TSB 74 HOLDEN VE WM HCM STRATEGIES UPDATED 24-5-2013.pdf
has the pin locations of where each new sensor goes. You need to add 6 pins to the X2 connector on the HCM loom.
Once you've got the car sufficiently spread out and all the new sensors are in, it goes like this:
Swap the single zone HCM for your dual zone one.
Pin the new sensors into the right locations on the X2 connector. I used pins yanked out of a spare HCM loom from the heater box I had spare.
Remove the passenger side blend actuator (more or less in the middle) so you can move the blend doors by hand. Hold the passenger side door all the way up, and poke the drivers side with a screwdriver or something, there's a slip join you have to defeat to make the blend doors move independently.
Once you've managed that...
Get your new actuator and open it up. Yep. Pull the star shaped rod out and turn it around so the long side sticks out the opposite side to where it was, and put the actuator back together. This actuator can then go straight into the drivers side blend door hole. If you're like me and got yourself a whole dual zone heater box, there's a plug just for this actuator you can seperate out of the loom. It goes to the X3 connector on the HCM. No cut-n-shut needed.
Put the dash back in. Don't force anything, it's all plastic and all breakable.
Re-assemble just enough crap to get the hvac controls back in. I'm using the Alpine hvac controller, so I just swapped it to DZ mode and went for it. You may have to get a whole new headunit or whatever. Now would be a GREAT time to do an IQ swap.
Test the thing, you may have to do an "actuator learn". Look that up, I can't remember, mine did it by itself.
Fire the car up, crank one side to cold and the other to hot. If it all worked you'll have two different temperature air streams and an exterior ambient temp reading. At this point I called it quits and applied beer to face, went back and finished re-assembly the next day.
Now: IQ and E3 gauges!
