Contents Wiring diagrams Section: Ignition Switch/steering Lock All sections

Steering Column Switches: Overview Mercury Montego III

Normal Operation

The ignition switch receives overload protected B+ power from the battery junction box (BJB) fuse 34 (30A) through circuit 1715 (RD). The ignition switch has 4 possible states

  1. OFF
  2. ACC
  3. RUN
  4. START

The ignition switch ACC circuit provides greater than 10 volts through circuit 1716 (GY/YE) to the smart junction box (SJB) when the key is in the ACC position.

The ignition switch RUN circuit provides greater than 10 volts through circuits 1050 (LG/VT) and 1716 (GY/YE) to the smart junction box (SJB) when the key is in the RUN position.

The ignition switch START circuit provides greater than 10 volts through circuits 1522 (DG) and 1050 (LG/VT) to the smart junction box (SJB) when the key is in the START position.

The ignition lock cylinder is the mechanical link to the ignition switch. When the ignition key is placed in the ignition lock cylinder and rotated through the ignition switch positions, the pinion rotates, moving the ignition switch to the desired position.