as far as i know you use all the focus loom as normal and just wire up the engine loom

the sierra cosworth engine loom is 7 wires ( 4wd sierra cos engine loom) 2wd are slightly different)

red/blue 12v+
black - switched igntion
brown/white - water temp
brown/green - oil light
red/black - fuel pump
blue- batt light
green - rev counter

so alls you do is find the sensor wires that go to your clock pad for the relevant sender wires, a direct 12v and a switched igntion 12v(switched igntion is 12v when car is running)

the fuel pump make a new fuel pump loom up and use the wire to activate the new relay

and rev counter focus use coil packs so if your not on coil pack you need to have an aftermarket rev counter or modify yours to suit dizzy