Not if the proximate cause is replacement of the coil wire. Are you sure you have the wire securely snapped on at each end?
Could beAlso check the starter solenoid and loose or corroded battery cablesand starter
Weak battery? Loose or corroded battery cable? Bad neutral or clutch safety switch? Bad ignition switch?
The 1986 Mercury Marquis does not have a fuel cutoff switch. The fuel pump does have a fuse, of which could render it as nonworking.
Seized engine? Weak or dead battery? Loose or corroded battery cables? Dead spot on starter? Bad starter? Bad starter solenoid? Bad neutral or clutch safety switch?
Well, It could be your battery or alternator or both needs to be replaced but it could just be loose or corroded battery cables
Could be a corroded firewall plug or a bad headlamp switch.
It could be, or a conductor [wire] that carries electrical current to the headlight could be cut or disconnected, or the headlight contacts in the lighting switch could be corroded or damaged from overheating.
Could be a bad inertia switch.
It could be the motor, switch, relay, corroded or dirty connector, damaged wire or blown fuse.
theres probably a switch by your feet, if you press is and it doesn't turn to low beams, try pulling up the carpet the switch could be corroded and bad.
It sounds like the main switch is malfunctioning and it should be replaced.
could be bad wiring