The car in Rob's guide is mine. It's still wired as shown.
By pushing the AC and rear demist (but actually the recirc button) buttons twice I mean that the Ph2 has latching buttons for those functions i.e. One press opens the switch, and the second press closes it, and it toggles between on and off.
The ph1 just has momentary switches i.e. The switch is only closed when you push it, it opens again when you release it.
What it means is that the car expects to recieve a 'burst' of power, which is what you get from a ph1 switch, as standard. But put a ph2 switch in there and one press means it's constantly on, as if you're holding the switch down. You have to press the switch again to break the contact (like lifting your finger off the ph1 switch). You can just press it once, and the AC will still work, but it cuts out when you select the highest fan speed. Therefore you need to push it twice for full functionality.