I would first check all the battery wires are on right, as ford put a red live in a black sheath, so this has sometimes inadvertantly been put onto earth.
The follow power route from battery to ignition, make sure it is switching the power as key is turned, and work from there.
With all these problems, allthough all fixable, may be less headache to get another(car) loom, there are only five wires that go between this and the engine loom, so really easy, I would get a loom from a ghia as that is what cossie was based on with all the toys etc.
tabetha