1999 Mercury Cougar Wiring Diagram Manual: Original - A Mechanic's Memoir The year is 1999. Boy bands ruled the airwaves, dial-up modems screeched their digital battle cries, and the Mercury Cougar, a sleek feline of a car, prowled the streets. But beneath its seductive curves lay a network of wires, a complex tapestry as intricate as a spider's web. For many Cougar owners, understanding.. "1999 Cougar Wiring Diagrams" Written for Mercury dealership mechanics, this factory-published original wiring diagram shows you how to follow the wiring from bumper-to-bumper. It will help you understand connector configurations, and locate and identify circuits, relays, and grounds.