For 1990-2009 cars

The driver and front passenger seats are heated using electric heater elements located in the seat cushions and seat backs. Voltage to the heater elements is controlled by the heated seat modules using inputs from the heated seat switches and the heated seat thermistors. The heated seat modules and thermistors are part of the lower seat cushion heater element assemblies. Ignition voltage is supplied to the heated seat switch assembly and is used to supply the heated seat switch signal voltage to the module and to illuminate the heated seat indicator during heated seat operation. The high/low switch signal circuit is referenced high in the module and is grounded by the heated seat switch through a series of internal resistors. The seat temperature is regulated by the module using an input from the thermistor located in the seat cushion. The thermistor is a temperature sensitive variable resistor and the module determines the seat cushion temperature by monitoring the signal voltage supplied to the thermistor. When the desired seat temperature has been reached the module will open and close the supply voltage to the heater elements as necessary in order to maintain the seat temperature.