How can i fix the A/C on my 2006 Ford Focus ST?

When i press the A/C button, it illuminates as expected, however the Air-Con does not work. I have traced the problem down to a missing control feed (+12V) to the A/C relay in the engine bay auxilliary fuse-box. The feed should come from pin 25 (grey/yellow wire) on the multi-way connector that plugs into the auxillary fuse-box. The A/C button does not feel like is of the mechanical latching type, it feels more like a momentry make contact type, therefore it is possible that there is an electronic interface between the A/C button and the feed (pin 25 on the multi-way auxilliary fuse box connector). It is definately not the A/C relay, or A/C fuse inside the same fuse box that is at fault, it is definately a missing +12v controll feed to the A/C relay. If i short out the N/O connections of the A/C relay, then this will result in the A/C to then work. I need some help as to where the control feed from the in-cab A/C switch goes before it actually gets to pin-25 on the auxilliary fuse box connector, as mentioned earlier, the A/C switch is non-latching, therefore it must supply a pulse to some sort of logic control Circuit i would guess. I have checked all fuses in the main fuse-box too.....