The STOP fuse applies the voltage at all times to the stoplamp switch. The TURN fuse applies the voltage to the transmission range switch contacts. The transmission range switch contacts close when the vehicle is in PARK. When the contacts close, with the ignition switch in the ON position or the START position, the current flows to the shift lock relay. When you press the brake pedal, the current flows through the closed contacts in the stoplamp switch to the coil in the shift lock relay. The shift lock relay grounds at G105. The coil energizes and closes the contacts. The current flows through the closed contacts in the shift lock relay to the shift lock solenoid. The shift lock solenoid grounds at G201. The solenoid energizes and allows the manual selector lever to move from the P position.