1997 DODGE NEON radiator

Downloaded from www.Manualslib.com manuals search engine HELPFUL INFORMATION
Circuit Z12 which supplies ground for the PCM
high current drivers, has the same termination point
as circuit Z11. The termination point is the left side
of the radiator closure panel.
If the system loses ground for the ganged circuits,
at the left side of the radiator closure panel, the vehi-
cle will not operate. Check the connection at the
ganged ground circuit eyelet.
DATA LINK CONNECTOR
Circuit A14 supplies battery voltage to the univer-
sal data link connector. Circuit A14 originates in the
Power Distribution Center (PDC) and connects to a
battery fed bus bar. A 20 amp fuse protects circuit
A14.
A twisted pair of wires, circuits D1 and D2, from
the Airbag Control Module (ACM) connect to the uni-
versal data link connector.
Ground circuit Z12 splices to two cavities of the
data link connector. The Z12 circuit also connects to
cavities 10 and 50 of the PCM connector.
Circuit D20 connects to cavity 75 of the PCM and
to the universal data link connector. Circuit D20 is
the SCI receive circuit for the PCM.
Circuit D21 connects to cavity 65 of the PCM and
to the universal data link connector. Circuit D21 is
the SCI transmit circuit for the PCM. The D21 cir-
cuit splices to the ABS module.
HELPFUL INFORMATION
The grounding point for circuit Z12 is the left side
of the radiator closure panel.
Circuit Z12 also supplies ground for the PCM high
current drivers and has the same termination point
as circuit Z11.
If the system loses ground for the ganged circuits
at the left side radiator closure panel the vehicle will
not operate. Check the connection at the ganged
ground circuit eyelet.
AUTOMATIC SHUT DOWN RELAY
The Automatic Shut Down (ASD) relay is located
in the Power Distribution Center (PDC). Power for
the coil and contact side of the relay is supplied on
circuit A14. This circuit is HOT at all times and pro-
tected by a 20 amp fuse located in the PDC.
The Powertrain Control Module (PCM) controls the
ground path for the coil side of the relay on circuit
K51. This circuit connects to cavity 67 of the PCM.
When the PCM supplies the ground path on circuit
K51 the contacts in the relay CLOSE connecting cir-
cuits A14 and A142. The A142 circuit is spliced and
supplies power to the generator, fuel injectors, PCM,
ignition coil, and heated oxygen sensors.
HELPFUL INFORMATION
²Refer to group 14 Fuel System, for additional
information.
²Check the 20 amp fuse located in the PDC.
FUEL PUMP MOTOR
Circuit A14 is a bus bar in the Power Distribution
Center (PDC) and connects to battery voltage. The
contact side of the fuel pump relay connects circuit
A14 and circuit A141. A 20 amp fuse in the PDC pro-
tects circuits A14 and A142.
Circuit A141 supplies voltage for the fuel pump
motor. Circuit Z1 provides ground for the fuel pump
motor. The grounding point for circuit Z1 is the right
rear wheel house.
Circuit F12 supplies voltage to the coil side of the
fuel pump relay. The Powertrain Control Module
(PCM) controls the ground path circuit for the coil
side of the fuel pump relay on circuit K31. Circuit
K31 connects to cavity 74 of the PCM.
HELPFUL INFORMATION
Circuit F12 originates in the fuse block where it
connects to a bus bar fed by circuit A21. In the
START and RUN position, the ignition switch con-
nects circuit A1 from the PDC to circuit A21. A 30
amp fuse in the PDC protects circuits A1 and A21.
Circuit F12 splices to feed the ABS control module,
EGR solenoid, Torque Converter Clutch (TCC) sole-
noid, leak detection pump, and the EVAP/Purge sole-
noid.
Circuit F12 also connects to a bus bar in the PDC.
The bus bar supplies voltage to the coil side of radi-
ator fan relay and A/C clutch relay, as well as the
fuel pump relay.
VEHICLE SPEED SENSOR
Circuit K7 supplies 8 volts from the Powertrain
Control Module (PCM) to the Vehicle Speed Sensor
(VSS). The K7 circuit connects to cavity 44 of the
PCM connector.
Circuit G7 from the VSS provides an input signal
to the PCM. The G7 circuit connects to cavity 66 of
the PCM connector.
The PCM provides ground for the VSS signal (cir-
cuit G7) through circuit K4. Circuit K4 connects to
cavity 43 of the PCM connector.
HELPFUL INFORMATION
Circuit G7 splices to the speedometer and odome-
ter in the instrument cluster.
Circuit K7 splices to supply 8 volts to the camshaft
position sensor and crankshaft position sensor.
Circuit K4 splices to supply ground for the signals
from the following:
²Upstream heated oxygen sensor
²Downstream heated oxygen sensor
PL8W - 30 FUEL/IGNITION SYSTEMS 8W - 30 - 15
DESCRIPTION AND OPERATION (Continued)

Downloaded from www.Manualslib.com manuals search engine ²Crankshaft position sensor
²Camshaft position sensor
²Battery temperature sensor
²Throttle position sensor
²Manifold absolute pressure sensor
²Engine coolant temperature sensor
²Knock sensor
²Intake air temperature sensor
HEATED OXYGEN SENSORS
Circuit A14 is a bus bar in the Power Distribution
Center (PDC), and connects to battery voltage. The
contact side of the Automatic Shut Down (ASD) relay
connects circuit A14 and circuit A142. A 20 amp fuse
in the PDC protects circuits A14 and A142.
Circuit A14 also supplies voltage to the coil side of
the ASD relay. The Powertrain Control Module
(PCM) controls the ground path circuit for the coil
side of the ASD relay on circuit K51. Circuit K51 con-
nects to cavity 67 of the PCM connector.
Circuit A142 splices to supply voltage for the
upstream and downstream heated oxygen sensors.
The A142 circuit also splices to cavity 6 of the
PCM. The input provided by circuit A142 at cavity 6
tells the PCM that the ASD relay energized.
Circuit K41 delivers the signal from the upstream
heated oxygen sensor to the PCM. Circuit K41 con-
nects to cavity 30 of the PCM connector.
Circuit K141 delivers the signal from the down-
stream heated oxygen sensor to the PCM. Circuit
K141 connects to cavity 51 of the PCM connector.
The PCM provides a ground for the upstream and
downstream heated oxygen sensor signals (circuit
K41 and K141) through circuit K4. Circuit K4 con-
nects to cavity 43 of the PCM connector.
Circuit Z1 provides ground for the heater circuits
in each sensor. Circuit Z1 terminates at the left side
of the radiator closure panel.
HELPFUL INFORMATION
Circuit A142 splices to supply voltage to the fuel
injectors, ignition coil, ASD relay, generator, and the
upstream and downstream heated oxygen sensors.
The PCM controls the ground circuit for each of the
components powered by circuit A142.
CRANKSHAFT POSITION SENSOR
Circuit K7 supplies 8 volts from the Powertrain
Control Module (PCM) to the crankshaft position
sensor. The K7 circuit connects to cavity 44 of the
PCM connector.
Circuit K24 from the sensor provides an input sig-
nal to the PCM. The K24 circuit connects to cavity 32
of the PCM connector.
The PCM provides ground for the crankshaft position
sensor signal (circuit K24) through circuit K4. Circuit
K4 connects to cavity 43 of the PCM connector.
HELPFUL INFORMATION
Circuit K7 splices to supply 8 volts to the camshaft
position sensor and vehicle speed sensor.
Circuit K4 splices to supply ground for the signals
from the following:
²Upstream heated oxygen sensor
²Downstream heated oxygen sensor
²Camshaft position sensor
²Battery temperature sensor
²Throttle position sensor
²Manifold absolute pressure sensor
²Engine coolant temperature sensor
²Knock sensor
²Intake air temperature sensor
²Vehicle speed sensor
CAMSHAFT POSITION SENSOR
Circuit K7 supplies 8 volts from the Powertrain
Control Module (PCM) to the camshaft position sen-
sor. The K7 circuit connects to cavity 44 of the PCM
connector.
Circuit K44 from the sensor provides an input sig-
nal to the PCM. The K44 circuit connects to cavity 33
of the PCM connector.
The PCM provides ground for the camshaft posi-
tion sensor signal (circuit K44) through circuit K4.
Circuit K4 connects to cavity 43 of the PCM connec-
tor.
HELPFUL INFORMATION
Circuit K7 splices to supply 8 volts to the camshaft
position sensor and vehicle speed sensor.
Circuit K4 splices to supply ground for the signals
from the following:
²Upstream heated oxygen sensor
²Downstream heated oxygen sensor
²Crankshaft position sensor
²Battery temperature sensor
²Throttle position sensor
²Manifold absolute pressure sensor
²Engine coolant temperature sensor
²Knock sensor
²Intake air temperature sensor
²Vehicle speed sensor
ENGINE COOLANT TEMPERATURE SENSOR
The engine coolant temperature sensor provides an
input to the Powertrain Control Module (PCM) on
circuit K2. The sensor also operates the engine cool-
ant temperature gauge in the instrument cluster on
circuit G20. Refer to Section 8W-40 for coolant tem-
perature gauge circuit description.
From circuit K2 the engine coolant temperature
sensor draws up to 5 volts from the PCM. The sensor
is a variable resistor. As coolant temperature
changes, the resistance in the sensor changes causing
8W - 30 - 16 8W - 30 FUEL/IGNITION SYSTEMSPL
DESCRIPTION AND OPERATION (Continued)

Downloaded from www.Manualslib.com manuals search engine ²Circuit K59 connects to cavity 58 of the PCM
connector.
²Circuit K60 connects to cavity 49 of the PCM
connector.
POWER STEERING PRESSURE SWITCH
The power steering pressure switch opens and
closes circuit K10 between the Powertrain Control
Module (PCM) and ground. Circuit K10 connects to
cavity 45 of the PCM connector.
Circuit Z12 provides ground for the power steering
pressure switch. The grounding point for circuit Z12
is the left side of the radiator closure panel.
TORQUE CONVERTER CLUTCH SOLENOID (TCC)
The Powertrain Control Module (PCM) operates
the TCC solenoid by providing a ground path on cir-
cuit K54. Circuit K54 connects to PCM cavity 79.
Circuit F12 supplies battery voltage to the TCC
solenoid. Circuit F12 connects to a bus bar in the
fuse block fed by circuit A21. A 15 amp fuse in the
fuse block, cavity 10, protects circuit F12. Circuit F12
connects to cavity 20 of the PCM connector.
HELPFUL INFORMATION
Circuit F12 splices to feed the ABS control module,
PCM, EGR solenoid, leak detection pump, and the
duty cycle EVAP/Purge solenoid. The F12 circuit also
connects to a bus bar in the PDC that supplies volt-
age to the coil side of radiator fan relay, A/C clutch
relay, and fuel pump relay.
In the RUN or START position, the ignition switch
connects circuit A1 from the fuse block and circuit
A21. Circuit A1 connects to battery voltage and is
protected by a 30 amp fuse in the PDC.
DUTY CYCLE EVAP/PURGE SOLENOID
Circuit F12 supplies battery voltage to the Duty
Cycle EVAP/Purge solenoid. The Powertrain Control
Module (PCM) switches ground path for the solenoid
ON and OFF through circuit K52.
Circuit F12 connects to a bus bar in the fuse block
fed by circuit A21. A 15 amp fuse in the fuse block,
cavity 10, protects circuit F12. Circuit F12 also con-
nects to cavity 20 of the PCM connector.
Circuit K52 connects to cavity 68 of the PCM, and
cavity 1 of the solenoid connector.
HELPFUL INFORMATION
Circuit F12 splices to feed the ABS control module,
PCM, EET solenoid, leak detection pump, and the
TCC solenoid. The F12 circuit also connects to a bus
bar in the PDC that supplies voltage to the coil side
of radiator fan relays, A/C clutch relay, and fuel
pump relay.
In the START or RUN position, the ignition switch
connects circuit A1 from the fuse block and circuitA21. Circuit A1 connects to battery voltage and is
protected by a 30 amp fuse in the PDC.
EGR TRANSDUCER (EET) SOLENOID
Circuit F12 supplies battery voltage to the EET
solenoid. The Powertrain Control Module (PCM)
switches ground path for the solenoid ON and OFF
through circuit K35.
Circuit F12 connects to a bus bar in the fuse block
fed by circuit A21. A 15 amp fuse in the fuse block,
cavity 10, protects circuit F12. Circuit F12 also con-
nects to cavity 20 of the PCM.
Circuit K35 connects to cavity 40 of the PCM con-
nector.
HELPFUL INFORMATION
Circuit F12 splices to feed the ABS control module,
PCM, Duty Cycle EVAP/Purge solenoid, leak detec-
tion pump, and the TCC solenoid. The F12 circuit
also connects to a bus bar in the PDC that supplies
voltage to the coil side of radiator fan relays, A/C
clutch relay, and fuel pump relay.
In the START or RUN position, the ignition switch
connects circuit A1 from the fuse block and circuit
A21. Circuit A1 connects to battery voltage and is
protected by a 30 amp fuse in the PDC.
LOW FUEL DETECT INPUT
Circuit G4 provides an input to the Powertrain Con-
trol Module (PCM) indicating fuel tank level. This cir-
cuit connects to cavity 23 of the PCM connector.
The G4 circuit is also used for the fuel gauge
located in the instrument cluster. For operation of
the fuel gauge, refer to section 8W-40.
PARK/NEUTRAL POSITION SWITCH INPUT (3±SPD
TRANSMISSION)
On vehicles equipped with the 3±spd automatic
transmission the park/neutral switch provides an
input to the Powertrain Control Module (PCM).
When CLOSED, the park/neutral position switch
provides a ground path on circuit T41 for the coil
side of the engine starter motor relay. The case
grounded switch provides ground for circuit T41.
Circuit A41 from the ignition switch provides bat-
tery voltage to the coil side of the relay.
Circuit T41 splices to cavity 76 of the PCM. The
park/neutral position switch provides an input to the
Powertrain Control Module (PCM).
HELPFUL INFORMATION
In the START position, the ignition switch connects
circuit A1 from the Power Distribution Center (PDC)
to circuit A41. A 30 amp fuse protects circuits A1 and
A41.
PL8W - 30 FUEL/IGNITION SYSTEMS 8W - 30 - 19
DESCRIPTION AND OPERATION (Continued)

Downloaded from www.Manualslib.com manuals search engine 8W-35 ANTI-LOCK BRAKES
INDEX
page page
DESCRIPTION AND OPERATION
ABS PUMP MOTOR RELAY................ 6
ABS SYSTEM RELAY..................... 6
ABS WARNING LAMP..................... 6
ANTI-LOCK BRAKES..................... 6BRAKE SWITCH INPUT................... 7
DATA LINK CONNECTOR.................. 7
HELPFUL INFORMATION.................. 7
HYDRAULIC MODULATOR................. 6
WHEEL SPEED SENSORS................. 7
DESCRIPTION AND OPERATION
ANTI-LOCK BRAKES
Power for the Anti-Lock brake system is supplied
by two fuses. There is a 15 amp fuse located in the
fuse block cavity 10. This fuse supplies power to the
Controller Anti Lock Brake (CAB), and the ABS sys-
tem relay on the F12 circuit. The F12 circuit also
supplies power to the Powertrain Control Module
(PCM). Power for the fuse is supplied on the A21 cir-
cuit from the ignition switch. This fuse is HOT in the
START/RUN position.
The second fuse is located in the Power Distribu-
tion Center (PDC). It is a 40 amp fuse. This fuse is
HOT at all times and supplies power to the contact
side of the ABS pump motor relay.
There are three grounding points used in the ABS
system. One is a case ground on the CAB. The sec-
ond is the Z12 circuit at the CAB connector cavity 5.
This ground is spliced, and terminates at the left side
of the radiator closure panel.
The third ground is on the Z1 circuit. This ground
is used for the ABS hydraulic modulator, ABS system
relay, and the ABS pump motor. This ground, like the
Z12 ground splices and terminates at the left head-
lamp ground.
Additional information on the circuit function of
the ABS system is listed below. For diagnostic and
testing procedures, refer to the appropriate section of
the Service Manual or the Diagnostic Test Proce-
dures Manual.
ABS WARNING LAMP
The ABS warning lamp is an output from the Con-
troller Anti Lock Brake (CAB) and the ABS relay
box. It is used to alert the operator of a problem in
the ABS system. The G19 circuit from the CAB and
the ABS system relay is used to detect a problem. If
a problem is detected, the CAB grounds the G19 cir-
cuit and illuminates the lamp in the instrument clus-
ter.
Circuit G19 is also an output of the CAB to the
ABS system relay contact side.
ABS SYSTEM RELAY
The system relay is used for the operation of the
ABS system. Power for the relay is supplied on the
B57 circuit from cavity 57 of the Controller Anti Lock
Brake (CAB).
Ground for the relay is on the Z1 circuit. This
ground is spliced in with the pump motor and termi-
nates at the left headlamp ground.
When the system is operating normally power for
the contact side of the relay is supplied from the
CAB on the B57 circuit. It passes through the relay
to the Z1 ground and terminates at the left headlamp
ground. If a problem is detected in the system, the
contact side of the relay switches from the Z1 to the
F12 circuit. This causes the ABS warning lamp in
the instrument cluster to illuminate.
ABS PUMP MOTOR RELAY
The ABS pump motor relay controls when the
pump motor runs. Power for the coil side of the relay
is supplied from cavity 47 of the Controller Anti Lock
Brake (CAB) on the B47 circuit. This circuit also sup-
plies voltage for the contact side of the system relay.
The ground side of the coil is controlled by the B116
circuit. Circuit B116 connects to cavity 16 of the CAB
connector.
Circuit B120 from cavity 20 of the CAB connector
powers the ABS pump motor. This circuit is also used
as an input to the CAB for pump motor monitoring.
HYDRAULIC MODULATOR
The hydraulic modulator is used for the controlling
of the brake system pressure to the wheels. The mod-
ulator is made up of four solenoids.
Circuits involved are, B142 for the left front wheel,
B143 for the right front wheel, B146 for the left rear
wheel, and B148 for the right rear wheel.
The solenoids use a common ground on the Z1 cir-
cuit. There are two Z1 circuits from the modulator.
Both of these grounds terminate at the left headlamp
ground, and are spliced in with the ABS pump motor
and the ABS system relay.
8W - 35 - 6 8W - 35 ANTI-LOCK BRAKESPL

Downloaded from www.Manualslib.com manuals search engine 8W-41 HORNS/CIGAR LIGHTER
DESCRIPTION AND OPERATION
HORNS
The horn system is powered by a 15 amp fuse
located in the Power Distribution Center (PDC)
which is HOT at all times on circuit F31. This circuit
supplies voltage to the coil and contact side of the
horn relay.
When the operator presses the horn switch, a
ground path is completed on the coil side of the horn
relay through the switch. The horn relay, located in
the PDC, then CLOSES the relay contacts. Voltage is
passed through the CLOSED relay contacts on circuit
X2 to the horn. Grounding for the horn is on the Z1
circuit to the left headlamp ground which is located
on the left side of the radiator closure panel.
HELPFUL INFORMATION
²Check the 15 amp fuse in the PDC.²Press the horn switch and listen for the horn
relay to click. A clicking relay indicates voltage is
present up to the switch.
²Check for a good ground at the left headlamp
ground.
CIGAR LIGHTER
The cigar lighter in this vehicle uses a cigar lighter
relay and a cigar lighter element. Power for the cigar
lighter relay is supplied by two sources.
Power for the coil side of the relay is supplied by
circuit F13. This circuit is protected by a 20 amp fuse
located in the fuse block. Power for the contact side
of the relay is supplied on circuit F38. The F38 cir-
cuit is protected by a 15 amp fuse.
Ground for the cigar lighter element and relay is
supplied on circuit Z1.
8W - 41 - 4 8W - 41 HORNS/CIGAR LIGHTERPL

Downloaded from www.Manualslib.com manuals search engine 8W-42 AIR CONDITIONING-HEATER
INDEX
page
SCHEMATICS AND DIAGRAMS........................................................... 1
DESCRIPTION AND OPERATION.......................................................... 6
Component Page
A/C Compressor Clutch................8W-42-2
A/C Compressor Clutch Relay...........8W-42-2
A/C Cycling Switch...............8W-42-3, 4, 5
A/C Heater Blower Motor..............8W-42-3
A/C Heater Control Switch...........8W-42-3, 3
A/C High Pressure Switch..............8W-42-5
A/C Low Pressure Switch............8W-42-4, 5
Blower Motor Resistor Block............8W-42-3
Diode..............................8W-42-2
Fuse 5 (FB).........................8W-42-4
Fuse 5 (PDC)........................8W-42-5
Fuse 7 (FB).........................8W-42-3
Fuse 9 (FB).........................8W-42-3
Fuse 10 (FB)........................8W-42-2
Fuse 18 (PDC).......................8W-42-2
Fuse Block......................8W-42-2, 3, 4Component Page
G101..............................8W-42-5
G103..............................8W-42-2
G203..............................8W-42-3
Headlamp Switch....................8W-42-3
Power Distribution Center...........8W-42-2, 5
Powertrain Control Module...........8W-42-2, 5
Radiator Fan Motor..................8W-42-5
Rear Fog Lamp Switch................8W-42-3
S108..............................8W-42-5
S109..............................8W-42-2
S111 ..............................8W-42-5
S204..............................8W-42-3
S210..............................8W-42-3
S211 ..............................8W-42-4
S314..............................8W-42-3
Solid State Fan Relay.................8W-42-5
8W - 42 - 2 8W - 42 AIR CONDITIONING-HEATERPL

Downloaded from www.Manualslib.com manuals search engine 30A
FUSE
5
5 73
BATT A0
POWER
DISTRIBUTION
CENTER
1
2A16
14
GY
RELAY FAN
STATE
SOLID
C2
18
K173
20
DG
K173
20
LG
13C160
Z1
18
BK
S111
Z1
14
BK
Z1
14
BK
C25
14
LG
Z1
14
BK
G101
S108
POWERTRAIN
CONTROL
MODULE MOTOR FAN
RADIATOR
4
13
BR18 C20
DB/OR22 C21
A/C
HIGH
PRESSURE
SWITCH A/C
LOW
PRESSURE
SWITCH
C2
38
DB/OR20 C21
C2063
2
1
2
1
C1605
SENSE SWITCHA/C
BR/OR20 C20
DB/WT20 C22
DB/OR22 C21
1
2
A/C
CYCLING
SWITCH
RADIATOR
FAN
RELAY
CONTROLA/C
CYCLING
SWITCH
OUTPUT
2C101
(8W-10-7)(8W-10-4)
(8W-15-2)
(8W-15-2) (8W-15-2)
(8W-30-11) (8W-10-4)
(8W-42-4)
M
PL-RHD8W-42 AIR CONDITIONING-HEATER 8W - 42 - 5
PLR04204978W-1

Downloaded from www.Manualslib.com manuals search engine 8W-42 AIR CONDITIONING-HEATER
INDEX
page page
DESCRIPTION AND OPERATION
A/C OPERATION......................... 6
AIR CONDITIONING-HEATER SYSTEM....... 6BLOWER MOTOR OPERATION............. 6
HELPFUL INFORMATION.................. 7
RADIATOR FAN OPERATION............... 6
DESCRIPTION AND OPERATION
AIR CONDITIONING-HEATER SYSTEM
The A/C-Heater System is powered by a by several
fuses. Fuse 10, a 15 amp fuse located in the fuse
block, is HOT in the RUN position. This fuse powers
the coil side of the A/C compressor clutch relay
located in the Power Distribution Center (PDC).
A 30 amp fuse, on circuit A16 located in the PDC,
powers the solid state radiator fan relay. This fuse is
HOT at all times. The 10 amp fuse on circuit A17
located in the PDC powers the contact side of the A/C
compressor clutch relay.
The A/C-Heater blower motor is protected by a 25
amp fuse located in cavity 7 of the fuse block. This
fuse in HOT in the RUN position only. When the
ignition switch is in the RUN position, power is sup-
plied to the fuse on circuit A22. The power leaves the
fuse on circuit C1 and goes directly to the blower
motor.
There is a 4 amp fuse located in cavity 12 of the
fuse block used for the illumination lamps in the A/C-
Heater control. The fuse is HOT at all times.
A/C OPERATION
When the A/C or the defrost switch is put in the
ON position, and the A/C cycling switch, low pressure
cut-out switch, and the high pressure switch are
CLOSED, the Powertrain Control Module (PCM)
receives a request for A/C.
After receiving this input, the PCM activates the
A/C compressor by grounding the C28 circuit on the
coil side of the A/C Compressor Clutch relay. Power
for the coil side of the relay is supplied on the bus
bar located in the Power Distribution Center (PDC).
With the coil energized, current flows from the 10
amp fuse in the PDC on circuit A17 through the
CLOSED contacts in the relay, on the C3 circuit to
the A/C compressor clutch.
The A/C compressor clutch receives this voltage
and creates a magnetic field energizing the clutch.
Ground for the coil is provided at the right headlamp
ground.
The connector at the A/C compressor has a diode
located in it. This diode is used to control the inducedvoltage resulting from the magnetic field collapsing
when the clutch is disengaged. The diode provides a
path for the voltage to protect other components and
systems.
The A/C compressor clutch relay is also used by the
PCM to disengage the compressor in a Wide Open
Throttle (W.O.T.) condition.
RADIATOR FAN OPERATION
The radiator fan system used in this vehicle uses a
solid state relay that controls the speed of the radia-
tor fan.
Power for the relay is supplied on circuit A16 This
circuit is HOT at all times and protected by a 30 amp
fuse located in the Power Distribution Center (PDC).
Ground for the coil side of the relay is controlled by
the Powertrain Control Module (PCM). When the
PCM determines the need for fan operation the PCM
supplies the ground path for circuit K173. This cir-
cuit connects to cavity 18 of the PCM connector.
From the relay circuit C25 connects to the radiator
fan motor(s). On vehicles equipped with the manual
transmission only one radiator fan is used. For vehi-
cles equipped with an automatic transmission there
are two radiator fans used.
Ground for the radiator fans is supplied on circuit
Z1.
BLOWER MOTOR OPERATION
With the ignition switch in the RUN position,
power flows from the 25 amp fuse, in cavity 7 of the
fuse block, to the blower motor. Blower motor speed
is controlled by the fan control switch located in the
instrument panel, and the resistor block.
Blower motor LOW speed operation is accom-
plished on the C4 circuit. When the control switch is
moved to the LOW speed position, current is passed
on the C7 circuit through the blower motor resistor
to the C4 circuit. It then flows through the blower
motor switch to the Z8 circuit. The Z8 circuit termi-
nates at a grounding point on the instrument panel
left center support.
The operation of the blower motor M1 and M2
speed operations is the same as the LOW speed
8W - 42 - 6 8W - 42 AIR CONDITIONING-HEATERPL