Discovery II
WIPERS AND WASHERS
DESCRIPTION AND OPERATION
84-17
Operation
Front intermittent wipe variable delay
The front intermittent wipe variable delay operation allows the driver to adjust the interval between wipes to suit local
conditions. Front variable delay operation activates when the following conditions are met:
l
Ignition switch in position I or II.
l
Front wash/ wipe switch is in the intermittent position.
The BCU receives the front intermittent wipe signal from the front wash/ wipe switch. The BCU receives a separate
signal from the variable delay switch, determines the delay interval from the front wash/ wipe switch position and
passes it on to the IDM. The IDM energises the front wiper relay to activate the front wiper motor.
If the delay duration is decreased during front variable delay operation, the wipers immediately operate once and then
the delay cycle is reset to the new duration.
If the delay duration is increased during front variable delay operation, the delay cycle is automatically increased by
the BCU.
Front low speed
Front low-speed operation activates when the following conditions are met:
l
Ignition switch is in position I or II.
l
Front wipe/ wash switch is in low speed position.
Selecting low-speed on the front wash/ wipe switch signals the IDM to energises the front wiper relay, which provides
power to the front wiper motor assembly.
Front high speed
Front high-speed operation activates when the following conditions are met:
l
Ignition switch is in position I or II.
l
Front wipe/ wash switch is in high speed position.
Selecting high speed on the front wash/ wipe switch allows power to flow from the switch directly to the wiper motor.
The high-speed input goes to a set of brushes in the wiper motor that are closer together than the low speed brushes.
These brushes allow the motor to run at a faster speed but with less torque.
Front washer
Front washer operation will only activate when the following conditions are met:
l
Ignition switch is in position I or II.
l
Front washer switch operated.
Flicking the front washer switch energises the front washer pump motor for 0.4 second. Holding the front washer
switch for longer than 0.4 second allows the front washer pump motor to run as long as the switch is held.
There are two front washer configurations. If the vehicle is fitted with programme wash/ wipe, and the front washer
pump motor is active for more than 0.5 second, the front wipers operate at low speed. The wipers continue to operate
for 4 seconds after the washer switch is released. In some markets, the driver must activate the front wipers after a
front washer operation.
The front washer operation has a higher priority than the variable delay operation. This means that if intermittent wipe
is active when a front washer operation is initiated, the wash cycle executes and the intermittent wipe is re-instated
at the end of the wash operation.
