I need some help on my daughter's '77 Maverick. The black wire is not connected to the ignition switch. It appears to have been attached to the end of the switch directly on the bakelite (or whatever plastic was used). The FM indicates I should have continuity between the purple-white wire and the black when the key is in the start position. My Motor wiring diagrams show this also. My Chilton shows a black wire connected to the 7/16" nut holidng the switch to the steering column. How would there be continuity between a contact and the plastic casing? Is something missing? Pictures of new switches on parts store websites do not show the switch clearly, but the black wire appears to be attached to the end of the switch (plastic). Anyone have thoughts or info on this? Thanks.