RL V6-3474cc 3.5L (1998)
Seat Heater: Description and Operation
How the Circuit Works
With the ignition switch in ON (II), battery voltage is provided through fuse 19 to the coil of the front seat heater relay. The coil of the relay is grounded
at G251 ('96-'97 and '99-'04) or G301 ('98). Battery voltage is provided through fuse 5 to the closed contacts of the energized relay to both seat heater
switches.
Two heaters are provided in each front seat. One is located in the seat cushion and the other in the seat back.
When the driver's seat heater switch is in the LO position, current flows in series through the seat heater switch, the BLU wire, and the cushion and back
seat heaters to G651. Current is limited because it is flowing through both seat heaters in series, making the seat warm enough for moderately cold
weather.
When the switch is in the HI position, current flows through the seat heater switch, the GRN wire, the circuit breaker and thermostat, and through the
cushion and seat back heaters in parallel. The cushion heater is grounded through the BLU wire and the driver's seat heater switch to G251. The seat
back heater is grounded at G651. Since the cushion and seat back heaters are now in parallel, current flow through them increases and the seat warms up
to its maximum temperature. The circuit breaker and thermostat in the seat cushion will open at 122 °F (50 °C) to maintain a constant seat temperature
and prevent overheating. The front passenger's seat heaters work the same way.
