Heated Rear Window: Operation

Heated rear window system is controlled by a three position switch with "ON", "OFF", and "OPEN" positions. Switch is spring loaded and returns to center ("OPEN") position from either "ON" or "OFF" positions. When switch is turned "ON", voltage is supplied to rear window grid and indicator light. When switch returns to "OPEN" position, sufficient current is provided to hold relay coil energized and relay contacts closed. The relay timer will maintain electric current for approximately 10-15 minutes or until ignition or control switch is turned "OFF".

Fig 1: Heated Rear Window Schematic (Cadillac)

Courtesy of GENERAL MOTORS COMPANY

Fig 2: Heated Rear Window Schematic (Oldsmobile Exc. Starfire)

Courtesy of GENERAL MOTORS COMPANY

Fig 3: Heated Rear Window Schematic (G.M. "H" Body Models)

Courtesy of GENERAL MOTORS COMPANY