Description - Heated Seats

Description - Heated Seats

Heated seats

The heated seat system is available on both manual seats and electric seats. The electrical sub-system consists of the following components:
- Seat heater switches.
- Seat heater elements.
- Temperature control unit (if electric seats are fitted).
- Temperature sensor (if electric seats are fitted).
- Thermostat (if manual seats are fitted).

Seat heater switches







The seat heater switches supply an ignition feed to either the temperature control unit (vehicles with electric seats) or directly to the seat heater elements (vehicles with manual seats). When a seat heater switch is operated, current flows to the seat heater elements causing them to heat the seat.

The ignition feed comes from fuse 15 in the passenger compartment fuse box.

Seat heater elements

The seat heater elements are located in the seat cushion and squab. The cushion and squab heater elements are wired in series. Total power consumption at 13.5 volts is approximately 115 Watts.

The cushion heater element has an input feed from the temperature control unit or heater switch and an output to the squab heater element, which outputs to earth.

Temperature control unit







The temperature control unit is only fitted to vehicles with electric seats. Feed back of the seat temperature is via a Negative Temperature Coefficient (NTC) sensor within the seat cushion. Resistance of this sensor changes with the temperature of the seat cushion allowing the temperature control unit to lower or raise the voltage to the seat heater elements to raise or lower their temperature.

An ignition feed is supplied via the seat heater switch. The temperature sensor supplies an input. Output is a supply to the cushion heater element and an earth.

Thermostat

On vehicles with non electric seats, the temperature is controlled by a thermostat located in the seat cushion. The thermostat interrupts the power supply when it reaches a pre-determined temperature.