how to trace the 3 wires that goes on the inhibitor switch on ford auto gearbox

[Slickzn70]

Hi All, I have a ford cortina mk4 automatic, its a 2L pinto engine, my problem is the inhibitor switch mounted on the gearbox has three pins and no wiring at all, looked inside dash nothing how do I trace and rewire inhibitor swith, your help greatly appreciated many thanks, Slickzn

[bortaf]

There is a plug on the drivers side of the trans tunnel (under the clutch pedal), lift the carpet and the inhibitor loom plugs in there