SP-Boxer, is yours the same, or do you have buttons for the different vent settings instead of that slider? I know the Australia and NZ DM ones have the buttons, but they're RHD.
Rasta SLO, can you do me a huge favor? Feel free to say no to this, though, because it takes some work. Can you take off the dashboard trim piece and take out the climate control and take a picture of the connections on the back? I can give you instructions based on the USDM confituration.
It will require taking out four screws on the radio trim piece, seven or eight screws on the dashboard trim piece (including three behind switch areas, which requires popping out the switches), two to take off the top of thee steering column surround, and two to remove the glovebox to get to the temp control cable. Then there are two to get the control box out, and you have to remove the temp control cable and unplug a couple of harnesses to slide it out all the way.
If that's too much trouble, feel free to say so, but it's in the interest of better HVAC controls for USDM cars.
