Battery positive voltage (B+) is applied at all times to the heated seat relay module. The heated seat relay module receive ground from G301 and G302. The system operates only when the ignition switch is in the ACCY or ON position. When you press the heated seat switch to the LOW position or the HI position, the heated seat relay module heated seat switch input circuit will be activated. The heated seat relay module then applies battery positive voltage (B+) to the heated seats. The heated seat relay module monitors the seat surface temperature through a thermistor. The heated seat module maintains a pre-determined temperature. The heated seat relay module will set the heated seat temperature to high when pressed to the HI position. The heated seat relay module determines between the heated seat HI or LOW positions from input circuits between the switch and module.