Q: How to remove and install a starter motor in a Mercury Grand Marquis?
A: To begin, detach the negative terminal of the battery. Then, raise the vehicle and securely support it on jackstands. Next, disconnect the large cable from the terminal on the starter motor. Remove the starter motor mounting bolts and detach the starter from the engine. If necessary, turn the wheels to one side for easier removal access. For the solenoid/starter assembly type, follow the same steps but also disconnect the solenoid terminal connections. Finally, installation is the reverse of removal.
Q: How to diagnose starter problems on Mercury Grand Marquis?
A: Before diagnosing starter issues, ensure a fully charged battery. If the starter motor doesn't turn, check the shift lever is in Neutral or Park and the battery is charged with secure cables. If the motor spins but the engine doesn't turn over, the starter motor may need replacing. If the motor doesn't operate but the relay/solenoid clicks, the problem could be the battery, relay/solenoid contacts, or motor connections; if it doesn't click, there may be an open circuit or a defective relay/solenoid. Check the circuit and test with a jumper wire and if the motor operates, the issue could be the ignition switch, Neutral start switch, or circuit wiring. If not, replace the relay/solenoid. If the motor cranks the engine slowly, ensure a fully charged battery, clean and tight terminal connections, and check for a short to ground. Consider a partially seized engine or incorrect oil viscosity.