MAZDA 323 1989 Factory Repair Manual

TROUBLESHOOTING GUIDE U
Symptom
Blower motor does not operate
Condenser fan does not opera!e
(Magnetic clutch operates normally)
--
Magnetic clutch does not operate
(Condenser fan operates normally)
Reference page
U- 6
U- 8
--
u-10
Condenser fan and magnetic clutch do not operate
lnsufficlent cooling
No cooling
Intermittent cooling u-12
u-14
03uoux-004
ELECTRICAL TROUBLESHOOTING TOOLS
Jumper Wire
The
jumper wire is used for testing by short-circuiting switch
terminals
and to verify the condition of ground connections.
Caution
l Do not connect the jumper wire between a power
source and a body ground. This may cause burn-
ing or other damage to harnesses and electronic
components.
Voltmeter
The DC voltmeter is used for measurement of circuit voltage.
A voltmeter with a ranqe of 15V or more must be used. It is
q
used by connecting th‘k positive (+) probe (red lead) to the
point where voltage is to be measured and connecting the
negative (-) probe (black lead) to a body ground.
Ohmmeter
The ohmmeter is used to measure the resistance between two
points in a circuit, to check for continuity, and to diagnose short
circuits.
Caution
l Never connect the ohmmeter to any circuit to which
voltage is applied. Doing so may burn or otherwise
damage the ohmmeter.
SMUOUX 010
U-5

U TROUBLESHOOTING GUIDE
Symptom: Blower motor does not operate.
Normal operation of blower motor
Blower motor speed is controlled by the blower switch and a resistor assembly in the blower unit.
When the blower switch is in the OFF position, the motor ground circuit is open and the blower motor does
not operate. When the switch is in the first (Low) position, current flow from the blower motor is restricted
by the three resistors in the resistor assembly, and the blower motor turns at low speed.
Changing the blower switch to the second (Mid), third (High), or fourth (Super-high) positions causes the
circuit resistance to decrease, and the blower motor speed to become correspondingly faster.
03uoux-005
. HEATER 30A
CIRCUIT
BREAKER
RED BUTTON
23UOUX-01
Step 1 Check circuit breaker
1. Check the circuit breaker.
ircuit breaker] Amperage ( Location
HEATER 1 30A Fuse box
2. If the reset button is not out, go to Step 2.
3. If the reset button is out, check for a short circuit in the har-
ness. Repair as necessary; then depress the reset button
to reset the circuit breaker.
Step 2 Measure voltage at blower motor
1. Turn the ignition switch ON.
2. Turn the blower switch to the fourth position.
3. Measure the voltage at the following terminal wires of the
blower motor connector.
VB: Battery voltage
Wire
Voltage Action
a-) VB Next, check wire (L/B)
ov ReDair wire harness
(Ciicuit breaker-Blower motor)
U-W VB Go to Step 3
ov Replace blower motor
U-6

TROUBLESHOOTING GUIDE U
23UOUX-004
Step 3 Measure voltage at resistor assembly
1. Turn the ignition switch ON.
2. Turn the blower switch OFF and verify that the A/C switch
is OFF.
3. Measure the voltage at the following terminal wires of the
resistor assembly.
VB: Battery voltage
Wire Voltage Action
u-w V0 Next, check wire (L/R)
ov Replace resistor assembly
0-w V0 Next, check wire (L)
ov Reolace resistor assembly
(L)
(L/Y) V0 Next, check wire (L/Y)
ov Replace resistor assembly
VB Go to Step 4
ov Replace resistor assembly
I
23UOUX-005
-.I
Step 4 Measure voltage at blower switch
1. Turn the ignition switch ON.
2. Turn the blower switch to the fourth position.
3. Measure the voltage at the following terminal wire of the
blower switch connector.
Ve: Battery voltage
Wire Voltage Action
W ov Go to Step 5
VB Repair wire harness
(Blower switch-Body ground)
1
23UOUX-00 6
Step 5 Measure voltage at blower switch
1. Turn the ignition switch ON.
2. Turn the blower switch and A/C switch OFF.
3. Measure the voltage at the following terminal wires of the
blower switch connector.
Ve: Battery voltage
Wire Voltage
WV ov
VB
(L/R) - OV
VB
u-) ov
VB
(L/Y) ov
VB Action
Repair wire harness
(Resistor assembly-Blower switch)
Next, check wire (L/R)
Reparr wire harness
(Resistor assembly-Blower switch)
Next, check wire (L)
Repair wire harness
(Resistor assembly-Blower switch)
Next, check wire (L/Y)
Repair wire harness
(Resistor assembly-Blower switch)
Replace blower switch
u-7

TROUBLESHOOTING GUIDE
Symptom: Condenser fan does not operate. (Magnetic clutch operates normally.)
03uoux-009
I 23UOlJX-007
WITH
MTX AND
fi==Tl (B/O)...BP ENGINE
-’ WITH ATX
Step 1 Check condenser fan operation
1. Disconnect the condenser fan connector.
2. Apply battery voltage to terminal a and ground terminal b
and verify that the condenser fan operates.
3. If the condenser fan does not operate, replace it.
4. If the condenser fan operates, go to Step 2.
Step 2 Measure voltage at condenser fan
1. Disconnect the condenser fan connector.
2. Run the engine at idle.
3. Turn the A/C and blower switches ON.
4. Measure the voltage at the following terminal wire of the con-
denser fan connector.
VB: Battery voltage
Wire
WV Voltage
VB
ov Action -
Replace condenser fan
Go to Step 2
Step 3 Measure voltage at condenser fan relay
Measure the voltage at the following terminal wires of the con-
denser fan relay connector.
(BP engine with ATX)
VB: Battery voltage
(BP engine with MTX and 66 engine)
Ve: Battery voltage
Wire Voltage Action
o-/W) VI3 Repair wire (L/W)
ov Next check wire (L/Y)
VY) VB Repair wire (L/Y)
ov Next check wire (B/L)
VW VB Repair wire (B/L)
ov Next check wire (B)
03 Va Repair wire (B)
ov Replace condenser fan relay ,
U-8

TROUBLESHOOTING GUIDE U
‘)
IO
1
Step 4 Measure voltage at refrigerant pressure switch
No.2
Measure the voltage at the following terminal wires of the
refrigerant pressure switch No.2 connector. VB: Battery voltage
Wire
WO)
(‘3 Voltage Action
VB Next check wire (B)
ov Repair wire (B/O)
V0 Repair wire (B)
ov Go to Step 5
Step 5 Measure refrigerant pressure
1. Connect the A/C manifold gauge set.
2. Operate the engine at 2,000 rpm and set the air condition-
er to maximum cooling.
3. Measure the high-pressure side refrigerant pressure.
Refrigerant pressure
Below: 1 ,177 kPa
(12 kg/cm*, 171 psi)
Above: 1 ,177 kPa
(12 kg/cm’. 171 psi) Action
Normal operation
Replace refrigerant pressure switch No.2
u-9

U TROUBLESHOOTING GUIDE
Symptom: Magnetic clutch does not operate. (Condenser fan operates normally.)
03uoux-015
_-I
I 23UOUX-011
Step 1 Measure voltage at compressor connector
1. Run the engine at idle.
2. Turn A/C and the blower switches ON.
3. Measure the voltage at the following terminal wire of the
compressor connector.
VB: Battery voltage
Wire
P/W Voltage
V0
ov Action
Go to Step 2
Go to Step 5
Step 2 Measure voltage at magnetic clutch connector
Measure the voltage at the following terminal wire of the mag-
netic clutch connector. Ve: Battery voltage
--
Wire Voltage Action
(B)
VB Go to Step 3
ov
t Go to Step 4
Step 3 Check magnetic clutch
1, Disconnect the magnetic clutch connector.
2. Check for continuity between the magnetic clutch and a
body ground.
Continuity
Yes
No Action
Adjust magnetic clutch clearance or
check for compressor internal trouble
Check ground wire
If ground wire OK, replace magnetic
clutch
Step 4 Check thermal protector
1. Turn the air conditioner OFF for about 10 minutes.
2. After 10 minutes, check for continuity of the thermal pro-
tector.
Continuity Action
Yes Normal operation
No Replace thermal protector .._

TROUBLESHOOTING GUIDE U
I 23UOUX-01
03UOUX-02
Step 5 Measure voltage at refrigerant pressure switch
No.1
Measure the voltage at the following terminal wires of the
refrigerant pressure switch No. 1 connector.
VB: Battery voltage
Wire
WV
W-) Voltage Action
V0 Repair wire (B/R)
ov Next check wire (B/L)
VB Go to Step 6
ov Repair wire (B/L)
Step 6 Measure refrigerant pressure
1. Turn the ignition switch OFF.
2. Connect the high-pressure hose of the manifold gauge to
the high-pressure gauge fitting.
3. Measure the refrigerant pressure at the high-pressure side.
High-pressure side:
Above 451 kPa (4.6 kg/cm2, 65 psi)
4. If not as specified, check the refrigerant system by refer-
ring to the troubleshooting information on page U-14.
5. If correct, replace refrigerant pressure switch No.2 with cool-
er pipe No.2. (Refer to page U-54.)
23UOUX-014
U-l 1

TROUBLESHOOTING GUIDE
Symptom: Condenser fan and magnetic clutch do not operate.
03uoux-023
r
3EAR WIPER 10A OA
L
03uoux-02.
I
1 Step 1 Check fuses
1. Check the following fuses.
Fuse Amperage Location
AD FAN 20A In main fuse box
REAR WIPER 10A In fuse box
2. If the fuse is burned, check for a short-circuit in the wiring
harness before replacing it.
3. If the fuses are OK, go to Step 2.
I
23uoux-011
Step 2 Measure voltage at A/C relay connector
1. Run the engine at idle.
2. Turn the A/C and blower switches ON.
3. Measure the voltage at the following terminal wires of the
A/C relay connector. VEX Battery voltage
,
Wire
0-Q
W) Voltage Action
VB Next check wire (L/Y)
ov Repair wire (L/G)
V0 Next check wire (B/L)
ov
VB
ov
VB
ov Repair wire (L/Y)
Repair wire (B/L)
Next check wire (LIB)
Go to Step 3
Replace A/C relay
Step 3 Measure voltage at A/C switch
Measure the voltage at the following terminal wires of the A/C
switch connectors.
VB: Battery voltage
Step 4 Measure voltage at thermoswitch
Measure the voltage at the terminal wires of the thermoswitch
connector.
VB: Battery voltage
Wire
(G/R)
WB)
Voltage
VB
ov
VB
OV
Action
Repair wire (G/R)
Next check wire (G/B)
Go to Step 5
Check ECU ooeration
1 -. [ Refer to Secti6n F
u-12

TROUBLESHOOTING GUIDE U
Step 5 Check thermoswitch
1. Turn OFF the A/C switch and set the blower switch to the
fourth position to operate the blower fan for a few minutes.
2. After a few minutes, turn OFF the blower switch and stop
the engine.
3. Disconnect the thermoswitch connector and check for con-
tinuity of the thermoswitch.
Terminals Continuity Action
a-b Yes Normal operation
No Redace thermoswitch
u-13

TROUBLESHOOTING GUIDE
I I
Symptom: Insufficient cooling.
No cooling.
Intermittent cooling.
I I
03uoux-110
SIGHT GLASS
o5uoux-020
Step 1 Checking refrigerant charge
1. Run the engine at a fast idle.
2. Operate the air conditioner at maximum cooling for a few
minutes.
3. Observe the sight glass to determine the amount of refriger-
ant and the related action as shown below.
Item Symptom Amount of refrigerant Action
1 Bubbles present in sight glass Insufficient refrigerant Check refrigerant pressure;
go to Step 2
2 No bubbles present in sight glass Too much or proper amount of Turn air conditioner OFF, and
refrigerant watch bubbles (Refer to Items 3
and 4)
__
3 Immediately after air conditioner turned Too much refrigerant Check refrigerant pressure;
OFF, refrigerant in sight glass stays clear go to Step 2
4 When air conditioner turned OFF, refrigerant
Proper amount of refrigerant Refrigerant amount normal
foams, and then sight glass becomes clear
9MUOUX-073
23UOUX-05i
Step 2 Checking refrigerant pressure
1. Connect the A/C manifold gauge set.
2. Operate the engine at 2,000 rpm and set the air condition-
er to maximum cooling.
3. Measure the low- and high-pressure sides.
(Refer to page U-37.)
Normal pressure
Low-pressure side:
147-294 kPa (1 J-3.0 kg/cm*, 21-43 psi)
High-pressure side:
1,177-1,619 kPa (12.0-16.5 kg/cm2, 171-235 psi)
4. If the pressures are not as specified, refer to the chart on
the next page and check the system.
u-14