Car won't start-replaced ignition switch on 1997 Grand Marquis.

Did it start before you replaced the switch ? Why did you replace the switch if the car started ? Who replaced the switch ? A repair shop or you ?

I would guess that one of the wires to the ignition switch or the switch itself is intermittent. Replacing ignition switch will likely fix it.

It likely is the place to start looking. Does the engine crank over but wont start, or nothing from the starter? If nothing, check for power on the small wire at the starter solenoid, when key is held in crank position. If no power, diagnose start wire from ignition switch to the starter solenoid. If power is at the small wire, but no starter action, recheck battery and starter connections, or have the starter tested.
If the starter works, but car won't run, recheck for spark at the sparkplugs. Have the fuel pressure tested-pressure is critical for injectors to work. If you still can't find the problem, your car needs shop time for diagnosis.

You may have a faulty Break-light switch. If the switch is bad, then it will behave as if you have no breaks afa the shift-lever is concerned.

We have the same problem on our 97 Grand Marquis. We have replaced the wiper blades and the drivers wiper arm with a used one. The problem was not completely solved but it did work better. We are going to replace the arm with a new one and see if that works better.

The ignition electrical switch itself is bad its along the steering column the fix is a replacement

Did you replace solenoid and ignition switch. I'd be checking grounds and the above 2 parts.

Either something came lose as it was not installed properly or something was dropped in the column to jam things up

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no..i also have an 85 gr. marquis with the 5.0 engine... i changed the starter solenoid located next to the battery on the passenger side firewall of the car.. if it clicks then its either the solenoid or the starter..those are hard to kill cars with good grounds..check the solenoid..