Operation

Seat Heating Operation
With the auxiliary circuits relay energised, the feed from fusible links 1 and 7 passes through the relay contacts and is connected to the passenger compartment fusebox on a WG wire where it passes through fuse 15.

From the passenger compartment fusebox, the feed is connected to header C0761 on an LGW wire. From the header C0761, the feed separates into two LGW wires which are connected to the LH and RH seat heater switches.

From the LH seat heater switch the feed is connected on a US wire to connector C0225-1/C0751-1 interface. From connector C0751-1 the feed continues on an OW wire to the LH seat heat module.

From the RH seat heater switch the feed is connected on a UK wire to connector C0253-1/C0751-1 interface. From connector C0751-1 the feed continues on an OW wire to the RH seat heat module.

Power is supplied to the electronics within the LH or RH seat heat module by the feed from the LH or RH seat heater switch. This allows the feed to pass through the module and is connected to the LH or RH seat cushion heater on a K wire. The LH or RH seat squab heater is connected in series from the LH or RH seat cushion heater on a KW wire. The LH and RH seat squab heaters are connected to earth header C0708 on B wires via splice joint 1

The earth from the LH or RH seat heat module is connected on an LG wire to a temperature variable resistor contained within each of the LH and RH seat cushion heaters. As the temperature of the seat cushion heater increases the resistance of the resistor changes. This is sensed by the seat heat module which varies the power supplied to the LH and RH seat cushion heaters raising or lowering their temperature accordingly.

The resistors are connected to the LH and RH seat heat module on B wires and from the LH and RH seat heat modules to earth header C0708 on B wires via splice joint 1.