1997 Mercury Grand Marquis Owner Guide 1st Printing - Page 17

This light illuminates every time you turn the ignition to the ON or START position (engine off). The light should go off when the engine starts and the alternator begins to charge. If the light stays on or illuminates when the engine is running, have the electrical system checked as soon as possible. Overdrive Off Indicator The overdrive off indicator light This light tells you that the Transmission Control Switch (TCS) has been pushed. When the light is on, the transmission will not shift into overdrive. Depressing the button will return the vehicle to "overdrive on" mode. The transmission will be in the "overdrive on" mode when the vehicle is started even if the O/D OFF mode was selected when the vehicle was last shut off. NOTE: If the light does not come on when the TCS is depressed or if the light flashes when you are driving, have your vehicle serviced at the first opportunity. If this condition persists, damage could occur to the transmission. 14