Discovery 2. Manual — part 333

WINDOWS

DESCRIPTION AND OPERATION

86-5-7

Rear window lift relay

The rear window lift relay is a normally open relay that provides power to the rear window system. It is controlled by
the IDM. The IDM receives a rear window enable signal from the BCU to allow operation during the ignition switched-
off timeout period.

Both the rear window lift relay and the IDM are located in the passenger compartment fusebox. The IDM is integral
to the passenger compartment fusebox.

The rear window lift relay receives voltage from fuse 13 (30A) in the passenger compartment fusebox. The IDM
controls the earth side of the relay coil.

TestBook cannot monitor the status of the rear window lift relay.

WINDOWS

86-5-8

DESCRIPTION AND OPERATION

Rear window switches

There are two sets of switches that operate the rear windows. There is a set of rear window switches located in the
centre console that allow the front seat occupants to operate the rear windows. The second set of switches are
located on the rear doors. All rear window switches are non-latching rocker switches.

A conventional window switch circuit controls the rear window system. In the rest position, there is battery voltage at
both sides of every switch as well as at the window motors. Operating any switch provides a ground path through the
switch to the window motor. Operating the switch in the opposite direction switches the voltage path and the earth
path to the motor allowing the motor to run in the opposite direction.

Voltage for the rear windows is from fuse 13 (30A) in the passenger compartment fusebox through the rear window
lift relay to the switches and motors.

TestBook cannot monitor the status of the rear window switches.

WINDOWS

DESCRIPTION AND OPERATION

86-5-9

Rear window isolation switch

The rear window isolation switch allows the front seat occupants to disable the rear window switches.

The rear window isolation switch is located in the centre console.

The rear window isolation switch is connected in the earth path in series with the rear door window switches.
Operating the rear window isolation switch interrupts the earth path to the rear door window switches, preventing the
rear door switches from operating the rear window motors. The rear windows can still be operated from the centre
console rear window switches.

TestBook cannot monitor the status of the rear window isolation switch.

WINDOWS

86-5-10 DESCRIPTION AND OPERATION

Rear window motors

There is a rear window motor located in each rear door. The rear window motors are permanent magnet motors with
an integral circuit breaker that provides stall protection.

The rear window switches provide battery voltage and an earth path to the rear window motors. Operating the switch
in the opposite direction reverses the voltage and earth paths at the rear window motor, allowing the motor to run in
the opposing direction.

TestBook cannot monitor the rear window lift motors.