DISCOVERY
K2 ETM
(Z228), P wire, closed contacts of the Rear A/C
Evaporator Temperature Switch (X260), and the
RG wire.
Compressor Control (300Tdi without EDC)
With the Ignition Switch (X134) in position II,
The Rear A/C Evaporator Temperature Switch
(X260) senses the temperature of the exterior fins.
Should ice begin to form due to low temperature,
the switch will open and the ground supply to the
Rear A/C Refrigerant Control Valve (K207) will then
be interrupted. The valve de–energises and
refrigerant flow is interrupted.
battery voltage is applied to the Ignition Load Relay
(K127). The relay is energized, applying battery
voltage to the Compressor Clutch Relay (K108).
When the Front Fan Speed Switch (X247) is turned
to positions I, II, III, or IV and the Front A/C Switch
(X225) is turned On, ground is provided to terminal
86
of the Compressor Clutch Relay (K108) through
the closed contacts of the A/C Dual Pressure
Switch (X102), the Front A/C Evaporator
Temperature Switch (X101), and the Compressor
Clutch Cut–out Switch (X259).
The Rear A/C Refrigerant Control Valve (K207) will
also be de–energised if one or more of the
following conditions occurs:
1.
The Front A/C Switch (X225) has been turned
OFF.
The relay is energized, applying battery voltage to
the Compressor Clutch (K107). Compressor Clutch
operation is now controlled by the status of the A/C
Dual Pressure Switch (X102), the Front A/C
Evaporator Temperature Switch (X101), and the
Compressor Clutch Cut–out Switch (X259).
2.
The Front Fan Speed Switch (X247) has been
turned OFF.
3.
4.
The Rear A/C switches have been turned OFF.
The Passenger’s Rear Fan Speed Switch
(X246) has been turned OFF.
The Front A/C Evaporator Temperature Switch
(X101) is fitted in the airflow out of the front
evaporator to sense the temperaure of the exterior
fins. Should ice begin to form, due to low
temperature, the switch will open. The A/C Dual
Pressure Switch (X102) monitors refrigerant
pressure in the high pressure line, should pressure
become too high or too low the switch will open.
When one or more of these switches open, the
ground supply to terminal 86 of the Compressor
Clutch Relay (K108) will be interrupted. The relay
de–energizes, removing battery voltage from the
Compressor Clutch (K107), disengaging the
Compressor.
5.
6.
The ECM determines that compressor clutch
operation is no longer required.
Compressor Clutch (K107) operation has been
disabled by the A/C Dual Pressure Switch
(X102) or the Front A/C Evaporator
Temperature Switch (X101).
7.
Compressor Clutch (K107) operation has been
disabled by the Compressor Clutch Cut–Out
Switch (X259) (300Tdi Without EDC Only).
Rear A/C Refrigerant Control Valve
When front A/C has been selected and the
Compressor Clutch (K107) is engaged, the
Compressor Clutch Relay (K108) is energised and
voltage is applied on the BG wires to the Rear A/C
Refrigerant Control Valve (K207). When rear A/C
is selected a ground signal is applied to the Rear
A/C Switch Amplifier (Z216). The Rear A/C Switch
Amplifier (Z216) then applies a ground signal to
energise the Rear A/C Control Relay (K194) and
the Rear A/C Fan Speed Relay (K205). When the
Passenger’s Rear Fan Speed Switch (X246) is in
any position other than Off, ground is applied to the
Rear A/C Refrigerant Control Valve (K207) through
the closed contacts of the Passengers Rear Fan
Speed Switch (X246), BR wire, closed contacts of
the Rear A/C Fan Speed Relay (K205), PG wire,
UB wire, Rear A/C Refrigerant Control Valve Diode
2
E L E C T R I C A L T R O U B L E S H O O T I N G M A N U A L
| Categories | Land Rover, Land Rover Discovery |
|---|---|
| Tags | Land Rover |
| Model Year | 1995 |
| Download File |
|
| Document Type | Electrical Troubleshooting Manual |
| Language | English |
| Product Name | Discovery |
| Product Brand | Land Rover |
| Document File Type | |
| Publisher | landrover.com |
| Wikipedia's Page | http://en.wikipedia.org/wiki/Land_Rover |
| Copyright | Attribution Non-commercial |
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