@Jack! Same has happened to me pal... The buttons on my original 05 climate control panel were shot so I bought another unit but that came from an older 172. I fitted that and the blower speed works fine but it always blows hot even on AC.
So can you swap buttons around? Easy enough to do?
Yeah, really easy actually.
On the climate panel there's 4 clips on the top and 4 clips on the bottom. You can't push the clips down, you have to lift the plastic frame over the clips, so I just used a small flat-head screwdriver to lift the casing over the clips in all 8 places. When you take that cover off the back of the unit, you'll be left with the front of the unit with the buttons in, there's a big motherboard/circuitboard type thing that is held in by 5 more clips (3 on the top 1 each side), you can easily see how they hold down the circuitboard and how to pry them to get the board out. Once the board is out, all the buttons just push out from the front of the unit. Swap the buttons over that need changing, put the board back on top and clip it back in and then clip the back casing back on.
Only thing of notice is when you lift the circuitboard out of the casing, the front little screen bit that shows you the readings on the climate panel has a pink bit of card, and then two bits of plastic, make sure they go back in the same order, pink card at the back of the unit.
