The seat heating power supply arrives via the relay T21 located in the fuse box in the boot B45; this is energized by the ignition-controlled line (INT/A) which arrives directly from the steering lock node M89; fuses F57 and F67, located in B45, protect the supply circuit for the two seats: the power supply for the two heaters O40 and O41 takes place via the control units M170 and M110 which receive commands from the switches I65 and I66.The switches are lit up with the ignition on (INT) by the line for fuse F49 of the junction unit under the dashboard B2.