1987 MAZDA 626 light

3B RADIATOR
Note
a) Position the hose clamp in the original location on the hose.
b) Squeeze the clamp lightly with large pliers to ensure a good fit. 86U03X-010
RADIATOR
REMOVAL AND INSTALLATION
1. Drain the engine coolant.
2. Remove in the sequence shown in the figure.
3. Install in the reverse order of removal.
1. Coolant reservoir hose
2. Fast idle solenoid
3. Coolant level sensor connector
4. Cooling fan connector
76G03B-005
5. Upper and lower radiator hose
6. Cooling fan and radiator assembly
7. Cooling fan
INSPECTION
Check the following points. Repair or replace if
necessary.
1. Cracks, damage, or water leakage
2. Bent fins (Repair with a screwdriver)
3. Distorted or bent radiator inlet
86U03X-012
3B-6

IDLE-UP CONTROL SYSTEM 4A
DUAL-SERVO DIAPHRAGM TYPE
With P/S and A/C
Solenoid valve (for P/S)
69G04B-124
Operation
A/C ON and compressor operating
Current flows through the A/C relay to the two-way solenoid valve for the A/C. Vacuum port A is opened,
and vacuum is applied to the servo diaphragm, which in turn pulls the throttle plates slightly open
at low speeds.
P/S operating
Current flows through the P/S switch to the three-way solenoid valve for power steering. Vacuum port
B is opened and vacuum is applied to the servo diaphragm, which in turn pulls the throttle plates slightly
open.
Relationship
Equipment
Type P/S A/C P/S & A/C
Single-servo
diaphragm type O O
Dual-servo
diaphragm type O
4A—69

4A IDLE-UP CONTROL SYSTEM
IDLE-UP SOLENOID VALVE
FE and F8 (General, ECE, Hong Kong, and Singapore)
Water thermo switch Fan speed control switch Headlights _
Rear defroster
A/C
Engine1
control -
unit
Richer air bleed
Richer jet
/ '
Inhibitor switch
Water thermo switch Fan speed _ control switch Headlights -
Rear defroster —
A/C
Engine
control
unit
Idle-up solenoid valve
Adjust screw
Secondary
throttle valve
From secondary main jet
76G04A-151
The idle-up solenoid valve opens when the following conditions are met.
Condition
When inhibitor switch is OFF (ATX—other than "P" and "N" range) and any of the following:
• Engine coolant temperature less than 72°C (162°F).
• A/C operated.
• Fan speed control switch 3rd or 4th position.
• Headlights turned on.
• Rear defroster turned on.
4A—76

4A CONTROL SYSTEM
RELATIONSHIP CHART
O: Related
X
: Not
related
IGNITION COIL
X X
O O O
X
O
X

WATER
THERMO
SWITCH
RADIATOR O O
X X X X
o O WATER
THERMO
SWITCH INTAKE
MANIFOLD o
X X X X
O o
X

VACUUM SWITCH
X X X X X X X
O
IDLE SWITCH
X X
O O O
X X X

A/C SWITCH
X X X X X
O
X X

P/S SWITCH
X X X X X X X X

E/L SWITCHES
/ Headlight Switch


( Rear defroster switch
J

\ Fan speed control switch
/
X X X X X
O
X X

INHIBITOR SWITCH
X X X X X
O O
X

ENGINE CONTROL UNIT
X
o O O O O o O

\
INPUT

DEVICE

AND
ENGINE

CONTROL

UNIT

OUTPUT
DEVICE
PTC
HEATER

CHOKE

OPENER
(FE
and
F8
—
ECE,
Hong
Kong,
&

Singapore)

COASTING
LEANER
COAST

ENRICHMENT

SOLENOID

VALVE
AIR

BYPASS
SOLENOID
VALVE
IDLE-UP
SOLENOID
VALVE
IGNITION
TIMING
CONTROL
SYSTEM
MAIN
AIR
BLEED
CONTROL
SYSTEM

*
FE
8Valve—Unleaded Fuel:
O
(Related)
General and
FE
12Valve—ECE, Hong Kong, Singapore:
X
(Not related)

76G04A-167
4A—84

4A CONTROL SYSTEM
ENGINE CONTROL UNIT
Check the engine control unit terminal voltages with
a voltmeter.
Caution
a) Warm up the engine before checking the
control unit.
b) If the proper voltage is not obtained, check
the wiring, connections and finally, check
the component.
FE and F8 Engine — ATX (ECE, Hong Kong, and Singapore)
Terminal
(Wire color) Connected to Condition Voltage

1A
(BW)
Ignition switch Ignition switch ON. Battery voltage

m
ST
'-O
Solenoid valve (Main
air
bleed control) Others Battery voltage
m
ST
'-O
Solenoid valve (Main
air
bleed control) Radiator coolant temperature below 17°C (63°F)
or
intake manifold vacuum more than 200 mmHg (7.9 inHg)
Below 1,5V
1C (GO) Solenoid valve (Choke opener) Radiator coolant temperature below 17°C (63°F)
or
during cranking and
27
sec. after engine starts Below 1,5V
Others Battery voltage
1D
(GL)
Air bypass solenoid valve Idle switch OFF and engine speed above approx. 2,100 rpm Below 1,5V
Others Battery voltage
1E
— — —

1F
(G) Solenoid valve (Ignition timing control system)
Radiator coolant temperature above 17°C (63°F),
en-
gine coolant temperature below 72°C (162°F), inhibi-tor switch OFF and engine speed below 2,300
rpm

Below 1.5 V
Others Battery voltage
1G
— — —

1H
(LW) Solenoid valve (A/C) A/C switch
ON
and engine speed below approx. 2,300
rpm

Below 1,5V
Others Battery voltage
11
(YW) Idle-up solenoid valve Inhibitor switch OFF and, headlight switch ON, rear
defroster switch ON, fan speed control switch
is 3rd

or 4th position, A/C operated,
or
engine coolant tem-
perature below 72°C (162°F)
Below 1,5V
Others Battery voltage
1J
(B)
Ground
—
Below 1,5V

9 MSSirSl
ivj
A 1
k *
76G04A-169
4A—86

CONTROL SYSTEM 4 A
Terminal
(Wire color) Connected to Condition Voltage

2A
(YL)
Ignition coil Ignition switch
ON or
engine running Battery voltage
2B (LB) Fan speed control switch Fan speed control switch
in
3rd
or
4th position Below 1.5 V 2B (LB) Fan speed control switch
Fan speed control switch OFF Battery voltage
2C
(BL)
Rear defroster switch Rear defroster switch
ON
Below 1,5V 2C
(BL)
Rear defroster switch
Rear defroster switch OFF Battery voltage
2D
(LG)
A/C switch A/C operated Below 1,5V 2D
(LG)
A/C switch
A/C not operated Battery voltage
2E
(RG)
Headlight switch Headlight switch OFF Below 1.5 V 2E
(RG)
Headlight switch
Headlight switch
ON
Battery voltage
2F
(GW)
Water thermo switch
(Radiator)
Radiator coolant temperature below 17°C (63°F) Below 1.5V 2F
(GW)
Water thermo switch
(Radiator) Radiator coolant temperature above 17°C (63°F) Battery voltage
2G
-— —

2H
(L)
Water thermo switch (In-
take manifold)
Engine coolant temperature below 72°C (162°F) Below 1,5V 2H
(L)
Water thermo switch (In-
take manifold) Engine coolant temperature above 72°C (162°F) Battery voltage
21
(LY)
Vacuum switch Vacuum less than 200 mmHg (7.9 inHg) Below 1.5V 21
(LY)
Vacuum switch
Vacuum more than 200 mmHg (7.9 inHg) Battery voltage
2J (RL) OD release solenoid valve Engine coolant temperature below 72°C (162°F) Below 1.5V 2J (RL) OD release solenoid valve
Engine coolant temperature above 72°C (162°F) Battery voltage
2K
(-)

— — -

2L (BR)
Inhibitor switch "N"
or "P"
range Below 1.5V 2L (BR)
Inhibitor switch
Others Battery voltage
2M (BY) Ignition switch
(START position)
Ignition switch
ON
Below 1,5V 2M (BY) Ignition switch
(START position) Cranking Battery voltage
2N
(LsB) Idle switch Idling Battery voltage 2N
(LsB) Idle switch
Accelerator pedal depressed Below 1,5V

76G04A-170

{ 2M 2K 21
X
2F 2C
2A

2N 2L 2J 2H 2F 2D 2B
(11 X X
1C 1 A^j
1J 1H 1F 1D 1B

FE and F8 Engine — MTX (ECE, Hong Kong, and Singapore)
Terminal (Wire color) Connected to Condition Voltage

A
(RG) Headlight switch Headlight switch
ON
Below 1,5V A
(RG) Headlight switch
Headlight switch OFF Battery voltage
B
(B)
Ground
—
Below 1,5V

4A-87

4A CONTROL SYSTEM
Terminal (Wire color) Connected to Condition Voltage

C (BL) Rear defroster switch Rear defroster switch
ON
Below 1,5V C (BL) Rear defroster switch
Rear defroster switch OFF Battery voltage
D
(LG) A/C switch A/C operated Below 1,5V D
(LG) A/C switch
A/C not operated Battery voltage
E (LY) Solenoid valve (Main
air
bleed control) Intake manifold vacuum more than 300 mmHg (11.8 inHg), and radiator coolant temperature above 17°C (63 °F)
Battery voltage E (LY) Solenoid valve (Main
air
bleed control)
Others Below 1,5V
F
(GW)
Water thermo switch
(Radiator) Radiator coolant temperature below 17°C (63°F) Below 1,5V F
(GW)
Water thermo switch
(Radiator) Radiator coolant temperature above 17°C (63°F) Battery voltage
G (YL)
Ignition coil Ignition switch
ON or
engine running Battery voltage
H
(L)
Water thermo switch (Intake manifold) Engine coolant temperature below 72°C (162°F) Below 1,5V H
(L)
Water thermo switch (Intake manifold) Engine coolant temperature above 72°C (162°F) Battery voltage
J (BW) Ignition switch Ignition switch
ON
Battery voltage
K (GO) Solenoid valve (Choke opener) Radiator temperature below 17°C (63°F)
or
during cranking and
27
sec. after engine starts Below 1,5V K (GO) Solenoid valve (Choke opener)
Others Battery voltage
L (LsB) Idle switch Idling Battery voltage L (LsB) Idle switch
Accelerator pedal depressed Below 1,5V
M
(GL)
Air bypass solenoid valve Idle switch OFF and engine speed above approx. 2,100 rpm Below 1,5V M
(GL)
Air bypass solenoid valve
Others Battery voltage
0
(BY)
Ignition switch
(START position)
Ignition switch
ON
Below 1,5V 0
(BY)
Ignition switch
(START position) Cranking Battery voltage
P
(LW) Solenoid valve (A/C) A/C switch
ON
and engine speed below approx.
2,300
rpm

Below 1,5V P
(LW) Solenoid valve (A/C)
Others Battery voltage
Q (YW) Idle-up solenoid valve Headlight switch ON, rear defroster switch ON,
fan
speed control switch
is
3rd
or
4th position, A/C oper-ated,
or
engine coolant temperature below 72°C (162°F)
Below 1,5V Q (YW) Idle-up solenoid valve
Others Battery voltage
R
(LB)
Fan speed control switch Fan speed control switch
in
3rd
or
4th position Below 1,5V R
(LB)
Fan speed control switch
Fan speed control switch OFF Battery voltage

76G04A-171

f ° O M K I G E C
R P N L J H F D B

4A-88

CONTROL SYSTEM 4 A
FE and F8 Engine — ATX (General)
Terminal (Wire color) Connected to Condition Voltage

1A
(BW)
Ignition switch Ignition switch
ON
Battery voltage
1B (GR) Solenoid valve (Main
air
bleed control) Others Battery voltage 1B (GR) Solenoid valve (Main
air
bleed control) Radiator coolant temperature below 17°C (63°F)
or
intake manifold vacuum more than 200 mmHg (7.9 inHg)
Below 1,5V
1C
— — —

1D
— — —

1E
— — —

1F
— --

1G
-—

1H
(LW) Solenoid valve (A/C) A/C operated Below 1,5V 1H
(LW) Solenoid valve (A/C)
Others Battery voltage
11
(LW) Idle-up solenoid valve Inhibitor switch OFF and, headlight switch ON, rear defroster switch ON, fan speed control switch
is 3rd
or 4th position, A/C operated,
or
engine coolant tem-perature below 72°C (162°F)
Below 1,5V 11
(LW) Idle-up solenoid valve
Others Battery voltage
1J
(B)
Ground
—
Below 1.5V
2A (YL) Ignition coil Ignition switch
ON or
engine running Battery voltage
2B (LB) Fan speed control switch Fan speed control switch
in
3rd
or
4th position Below 1.5V 2B (LB) Fan speed control switch
Fan speed control switch OFF Battery voltage
2C
(BL)
Rear defroster switch Rear defroster switch
ON
Below 1,5V 2C
(BL)
Rear defroster switch
Rear defroster switch OFF Battery voltage
2D
(LG) A/C switch A/C operated Below 1,5V 2D
(LG) A/C switch
A/C not operated Battery voltage
2E
(RG)
Headlight switch Headlight switch
ON
Below 1,5V 2E
(RG)
Headlight switch
Headlight switch OFF Battery voltage
2F
(GW)
Water thermo switch
(Radiator)
Radiator coolant temperature below 17°C (63°F) Below 1.5V 2F
(GW)
Water thermo switch
(Radiator) Radiator coolant temperature above 17°C (63°F) Battery voltage
2G
— — —

2H
(L)
Water thermo switch
(Intake manifold) Engine coolant temperature below 72°C (162°F) Below 1,5V 2H
(L)
Water thermo switch
(Intake manifold) Engine coolant temperature above 72°C (162°F) Battery voltage
21 (LB)
Vacuum switch Vacuum less than 200 mmHg (7.9 inHg) Below 1.5V 21 (LB)
Vacuum switch
Vacuum more than 200 mmHg (7.9 inHg) Battery voltage
2J
(RL)
OD release solenoid Engine coolant temperature below 72°C (162°F) Below 1,5V 2J
(RL)
OD release solenoid
Engine coolant temperature above 72°C (162°F) Battery voltage

4A-89