you are correct, very simple to do. i also had this problem, i bought a brand new one from ford too cos at the time i had no idea where to begin looking.....£40+

Anyway, theres 3 contacts......at idle, the centre pin should have a continuity reading with one of the two outside pins (sorry cant remember which ) and then when u pull the throttle fully open, those two should go open circuit (no continuity reading), and the other outside pin should have a reading with the centre one, simple as that, 2 switches inside is all it is.

it'll soon become obvious if it is fooked, eratic and/or no readings.

Best to do it with the plug disconnected to

let me know how u get on