^7?
Air Conditioning
System Fault Diagnosis
Blower Motor Test
Face Level: Hot Face Temperature Demand Switch: Minimum
Differential temp. 28 0 to 200mV
Temperature demand 35 0 to 200mV
Hote:
Allow
the servo motors
to
come to rest before checking voltage
levels.
Typical figures are given
in
brackets.
Mode Switch
Position
Low
Med
High
RH Control
Pin No. 32
1 - 2V (1.77V)
3V (2.28V)
2v
(1.1
7V)
Set Face Differential Pot. to Mid Point
Mode Switch RH Control
Position Pin No. 32
Low 1 - 2V (1.24V)
Medium 1 - 2V (1.4V)
High 2-3V(2.2V)
Set Face Differential Pot. to Cold Face
Mode Switch
Position
Low
Medium
High
RH Control
Pin No. 32
1 - 2V(1.67V)
2 - 3V(2.17)
2 - 3V(2.3V)
LH Control
Pin No. 31
1 -2V(1.77V)
2 - 3V (2.27V)
1 - 2V (1.19V)
LH Control
Pin No. 31
1 - 2V (1.27V)
1 - 2V (1.4V)
2 - 3V (2.2V)
LH Control
Pin No. 31
1 - 2V(1.63V)
2-3V(2.1V)
2 - 3V(2.2V)
RH Feedback
Pin No. 33
4 - 6V (5.8V)
3 - 5V (3.7V)
1 - 2V (1.22V)
RH Feedback
Pin No. 33
6.5 - 9V (8.7V)
6.9 - 9V (7.5V)
3-5V(4.1V)
RH Feedback
Pin No. 33
6.5 - 9V(6.25)
3 - 5V(4.25V)
3 - 5V (3.7V)
Open Water Temperature Switch Needs
Set Temperature Demand Switch to Midpoint Pin No. 35 1.43 -145V
RH Servo control Pin 32
LH Servo control Pin 31
Short Water Temperature Switch Leads
Mode Switch: Low
Clutch output
RH Servo control
LH Servo control
Set d iff to hot face
Set temp demand to minimum
Recirc. output
High speed relays
Water valve solenoid
Centre vent solenoid
Defrost output
MODE SWITCH: DEFROST
High speed relays
Lower feedback pot.
Upper feedback pot.
MODE SWITCH: OFF
Recirc. output
Pin 20
Pin 32
Pin 31
Pin 28
Pin 35
Pin 3
Pin 16
Pin 17
Pin 18
Pin 27
Pin 27
Pin 16
Pin 29
Pin 30
Pin 44
Pin 3
LH Feedback
Pin No. 22
4 - 6V (5.63V)
3 - 5V (3.4V)
1 -2V (1.27V)
LH Feedback
Pin No. 22
6.5 - 9V (8.7V)
6.5 - 9V (7.5V)
3 -5V (4.0V)
LH Feedback
Pin No. 22
6.5 - 9V(6. IV)
3 - 5V(4.2V)
3 - 5V(3.SV)
0.5V
0.5V
9.3-12.3V
1 -2V
1 -2V
0 - 200mV
0 - 200mV
9.3-12.3V
0 - 200mV
9.3-12.3V
9.3-12.3V
0 - 500mV
150-350mV
9.3-12.3V
2.709-3.1 OOV
1.714-2.014V
0-IV
9.3-12.3V
May 1996 8-33
^?
Air Conditioning
Sanden Compressor SD7H15
Sanden Compressor SD7H15
The Sanden SD7H15 compressor
is a 7
cylinder
machine with
a
bore
of
29.3
mm (1.15 in) and a
stroke
of
32.8
mm (1.29
inches).
The displacement
per
revolution
is
155cc
(9.5
cubic inches).
The magnetic clutch
is
engineered with
the
compressor
as a
complete assembly resulting
in a
relatively small unit
of
lightweight construction.
The compressor may be mounted up to 90° from
its
upright position.
The compressor incorporates
a
lubrication system
which reduces the
oil
circulation ratio
to a
level
of
less than
2% at 1800 rpm.
An
oil
deflector
and
positive pressure differential
lubrication system promotes oiling
to the
cylinder
wall,
piston
rod
assemblies, main bearings
and
shaft
seal,
and
ensures that
oil
circulation
to the
refrigeration circuit
is
kept
to a
minimum.
The
compressor ischarged
with!
35 cc(4.6fluid ounces)
ofSunico NoSGSoil at the factory. Only this oil
or
oneoftheequivalentoilsdetailed below should
be
used.
Key
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
to Fig. 2.
Service port
Cylinder head
Hose connection
Anti-rotation gear
Oil filler plug
Planet plate
Clutch bearing
Electromagnetic clutch
Valve plate assembly
Cylinder and valve plate gasket
Cylinder block
Piston
Cam rotor
Needle thrust bearing
Front housing and 'O' ring
Shaft seal
Compressor Oils
Suni
CO
No 5GS
Texaco Capella E
Virginia Chemicals 500 Viscosity
13
14 15 16
Figure
2.
May
1996
8-37
Air Conditioning
Portable Diagnostic Unit - Signal Monitoring 3^^?
Air Conditioning Signal Monitoring
The following signals can be monitored using the PDU. The abbreviated name of the signal is shown on the PDU
display.
Display Name Full Signal Name
AMBTEMP Ambient temperature sensor
ARECIP Auto-Recirculation input
ARECOP Auto-Recirculation output
AUX+ Auxiliary battery positive
CLUREL Clutch relay drive output
CVSOL Centre vent solenoid
DEFSOL Defrost solenoid
DIFF Temperature differential
EVSEN Evaporator sensor
FANDEF Fanspeed defrost
FANHIG Fanspeed high
FAN LOW Fanspeed low
FANMED Fanspeed medium
FIVEV Five volt supply voltage
FORSERL Lower servo forward drive
FORSERU Upper servo forward drive
GND10 Ground voltage
GND2 Ground voltage
GND38 Ground voltage
GND45 Ground voltage
GND6 Ground voltage
HSREL High speed relay drive
ICSEN In-Car sensor
LBLOFB Left blower feedback voltage
LBLOWOP Left blower output voltage
LSERFB Lower servo feedback potentiometer
MPROBE Measurement probe
POWIN+ Switched power input
POWOP+ Power output
RBLOFB Right blower feedback voltage
RBLOWOP Right blower output voltage
REF Reference signal
REVSERL Lower servo reverse drive
REVSERU Upper servo reverse drive
TEMPDEM Temperature demand
USERFB Upper servo feedback potentiometer
WATSW Water switch
WATVAL Water valve
8-66 May 1996
Air Conditioning
Portable Diagnostic Unit - Signal Definitions ^27
Defrost Solenoid
(DEFSOL)
Temperature Differential
(DIFF)
Evaporator Sensor
(EVSEN)
Fanspeed Defrost
(FANDEF)
Fanspeed High
(FANHIG)
Fanspeed Low
(FAN LOW)
A/CCM Pin 11 ref Pin 6
The defrost solenoid controls the operation ofthe screen vents. When the solenoid
is energised, the screen vents will be held closed by the vacuum created. To open
the vents the solenoid is de-energised.
The solenoid is energised when a ground supply is provided to pin 11. The
solenoid is de-energised when the ground supply is removed, at which point 10+
volts can be read at pin 11.
A/CCM Pin 28 ref Pin 6
This sets the differential between the position ofthe upper and lower flaps. With
minimum differential selected, pin 28 should read between 0 and 100 millivolts.
The voltage at pin 28 will rise smoothly as the differential is increased, up to a
maximum of 2.885 volts.
A/CCM Pin 5 ref Pin 6
This sensor monitors the temperature of the evaporator matrix, the output is used
to trigger the compressor circuit via the A/CCM pin 20. Operating conditions are
2.732 volts at 0 degrees Celsius ±0.01 volts for every degree Celsius above or
below zero.
A/CCM Pin 27 ref Pin 6
This signal is normal ly held at 3.6 ±0.8 volts by the control module. When Defrost
is selected from the control panel, the line is pulled down to 0.6 volts or below.
This will cause the defrost flaps to open by applying system voltage (approx 11
volts) to pin
11.
In addition, both fans will go to full speed i.e. high speed fan relay
energised .
A/CCM Pin 15 ref Pin 6
This signal is generated from the fan speed control switch.
Switch at High, pin
1
5 should read 0.6 volts.
Switch at Off, L, M or D positions, pin 15 should read 3.6 ±0.8 volts.
A/CCM Pin 13 ref Pin 6
This signal is generated from the fanspeed control switch.
Switch at Low, pin 13 should read 0.6 volts.
Switch at Off, M, H or D positions, pin 13 should read 3.6 ±0.8 volts.
8-68 May 1996
