Discovery 2. Manual - part 245

 

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Discovery 2. Manual - part 245

 

 

SEATS

DESCRIPTION AND OPERATION 76-5-11

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:

l

Seat heater switches.

l

Seat heater elements.

l

Temperature control unit (if electric seats are fitted).

l

Temperature sensor  (if electric seats are fitted).

l

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.

SEATS

76-5-12 DESCRIPTION AND OPERATION

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.

SEATS

DESCRIPTION AND OPERATION 76-5-13

Operation - heated seats

When the seat heater switch is operated, power is supplied to the heater elements in the seat, causing the seat to 
heat up. On vehicles fitted with non electric seats, the thermostat switches the power supply to the heater elements 
on and off. On vehicles fitted with electric seats, the temperature control unit senses seat temperature via the sensor 
in the cushion and regulates voltage to the seat heater elements to maintain a constant temperature.

On both electric and non electric seats, the heater elements increase and then maintain the seat at a temperature 
between 26 and 36 

°

C (79 and 97 

°

F).

 

 

 

 

 

 

 

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