If the clocks are the same ignition type ie coilpack then all that's needed as said is a feed from one side of the coil, ie a negative, which is the outer wires on the coilpack, just see what colour they are and use one.
Getting the old connector from the car the clocks came from is always a good idea as you can see any differences then and copy them, on the older fords it was only a case of moving 1 wire and adding 1 more when going to tacho.
tabetha