Grandma sucking eggs and all that but suspect the air con control panel to ECU is needed so that the ECU can tell when the a/c is
on and hence imposing compressor load...
But you already knew that I suspect....
Agree Jon, a bit of thought brought me to the same conclusion, a branch of one of the wires ends up at the tacho! Which makes sense!
The trouble with this loom is that you have to work out what you need and what you can do without! I have successfully traced about 100 wires from 3 multiplugs from the engine/trans and the body side of the ECU plug to their destinations all over the car, a lot seem quite simple and logical, others go to weird places like the ABS block and relay blocks that have no relay in them! What I don't want to do is discard some apparently useless lead that stops the engine from running! Most of these wierd and wonderful leads split up and go to several places and my thinking is that if one or two end up somewhere useful, the other branches can be discarded. But I am minded of a mate who put a Williams 172 engine in an earlier, smaller, Clio. He put the loom in with it but a numpty had cut the ABS plug and wires off - and it wouldn't run until he reinstated the plug AND the ABS block! Amid much swearing and gnashing of teeth! Several wires go to the Chip reciever that fits around the steering lock (yes I kept this - and the key with chip that matches it!), so of course then I had to trace ALL the other leads out of it, to make sure that doesn't stop it! And so on! It really is turning into the 8th labour of Hercules! Still, I suppose it could be worse, it could be CanBus!