relay FORD FESTIVA 1991 User Guide

COOLING FAN DOES NOT RUN WITH A/C ON
If cooling fan does not run with A/C on, check the following items to help isolate fault.
Check A/C cooling fan relay.
Check cooling fan wiring harness.
TESTING
VOLTAGE SUPPLY TEST
Disconnect cooling fan motor connector. Turn ignition on. Check for voltage at Yellow wire terminal of connector. If voltage is NOT present,
check for blown 20-amp COOLING fuse (Capri) or C-FAN fuse (Festiva) or open in Yellow wire between cooling fan and fuse.
Disconnect cooling fan relay connector. Cooling fan relay is located in the left front corner of engine compartment. Turn ignition on. Check
for voltage at Yellow (Capri) or Black/Yellow (Festiva) wire terminal of connector. If voltage is NOT present, check for blown 30-amp
HEATER fuse on Capri or 10-amp METER fuse on Festiva or open in Black/Yellow wire between cooling fan relay and fuse.
Disconnect A/C cooling fan relay connector. On Capri, A/C relay is located in the left rear corner of the engine compartment, on firewall. On
Festiva, A/C relay is located in the left front corner of engine compartment, under a triple relay cover. Relay may be identified by wire colors
to relay connector. See Fig. 2
and Fig. 3 . Turn ignition on. Check for voltage at Blue wire terminal of connector. If voltage is NOT present,
check for blown 15-amp HEATER fuse or open in Blue wire between A/C cooling fan relay and fuse.
GROUND CIRCUIT TEST
Turn ignition off. Unplug connectors from cooling fan and A/C cooling fan relays. Check for continuity between ground and Black wire
terminal of relay connectors. If continuity is NOT present, repair Black ground wire.
FAN MOTOR TEST
Disconnect fan motor wire connector. Apply ground and battery voltage to motor connector. Fan should run. If fan does not run, replace
cooling fan motor.
COOLING FAN RELAY TEST
Unplug cooling fan relay connector. Apply battery voltage and ground to Yellow and Green/Red (Capri) or Black/Yellow and Green/Yellow
(Festiva) wire terminals of relay. Check continuity of relay across Yellow/Green (Capri) or Yellow/Red and Black (Festiva) wire connector
terminals. Ensure continuity is NOT present while relay is energized. When relay is de-energized, continuity should exist.
A/C COOLING FAN RELAY TEST
Unplug A/C relay connector. Apply battery voltage and ground to Blue and White (Capri) or Blue and Green (Festiva) wire terminals of relay.
Check continuity of relay across Blue and Red (Capri) or Yellow/Red and Black (Festiva) wire connector terminals. On Capri, ensure
continuity does NOT exist while relay is energized. On Festiva, ensure continuity exists while relay is energized. On Capri, when relay is de-
energized continuity should exist. On Festiva, when relay is de-energized, continuity should NOT exist.
COOLANT TEMPERATURE SWITCH TEST
Disconnect connector from coolant temperature switch located in thermostat housing. With coolant temperature less than 200°F (93°C) for
Capri or 194°F (90°C) for Festiva, check continuity between ground and coolant temperature switch. Ensure continuity exists. Start engine
and allow coolant temperature to reach 200°F (93°C) for Capri or 207°F (97°C) for Festiva. Check continuity between ground and coolant
temperature switch terminal. Continuity should NOT be present. If switch does not test as indicated, replace switch.
HARNESS & CIRCUIT CHECK TEST
Turn ignition off. Disconnect harness connectors of the following components: ECA, cooling fan motor, coolant temperature switch, cooling
fan relay and A/C cooling fan relay. Using an ohmmeter, check for continuity on the related harness leads of each connector. See Fig. 2
and
Fig. 3
.
WIRING DIAGRAMS
For further detail, see appropriate chassis wiring diagram in the WIRING DIAGRAMS article in the WIRING DIAGRAMS section.
Page 2 of 3 MITCHELL 1 ARTICLE - ENGINE COOLING FAN 1990-92 ENGINE COOLING Ford Motor Co. Engine Cooling Fans
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Fig. 2: Capri Fuel System Electrical Schematic
Courtesy of FORD MOTOR CO.
Fuel Pump Relay
Remove fuel pump relay (located near heater duct under carpet). Apply positive 12 volts to relay terminals "A" and "B" together. See Fig. 3 .
Measure voltage between terminal "C" and ground, while individually grounding terminals "D" and "E". Ensure voltage is as specified. See
FUEL PUMP RELAY SPECIFICATIONS
table. If voltage is not as specified, replace relay.
FUEL PUMP RELAY SPECIFICATIONS

Fig. 3: Identifying Fuel Pump Relay Terminals

Courtesy of FORD MOTOR CO.
IGNITION CHECKS
Firing Order
Inspect spark plug wiring routing. Ensure firing order is 1-3-4-2.
Spark
1. Crank engine. Check for a strong Blue spark at each spark plug wire by using a high output spark tester. Ensure resistance of each spark
plug wire is 4000-6000 ohms per foot.
2. Disconnect and inspect all related ignition system connectors and harness. Clean or repair as necessary, and recheck spark. If st il l n o
spark, go to IGNITION COIL POWER SOURCE
.
Ignition Coil Power Source
Disconnect primary wires at ignition coil. Turn ignition on. Measure voltage between Black/White wire on harness connector and ground. If
voltage is not greater than 10 volts, check battery feed, ignition switch and fusible links. If voltage is greater than 10 volts, go to IGNITION
COIL RESISTANCE .
Ignition Coil Resistance
Measure resistance between primary terminals of coil. Measure resistance between positive primary terminal and coil tower. See IGNITION
COIL RESISTANCE table. Verify resistance between coil case and primary positive terminal is infinite. Replace coil if resistance
measurements are not within specifications.
IGNITION COIL RESISTANCE
IDLE SPEED & IGNITION TIMING
Ensure idle speed and ignition timing are set to specification. For adjustment procedures, see ON-VEHICLE ADJUSTMENTS article.
SUMMARY
If no faults were found while performing BASIC TESTING , proceed to TESTS W/CODES article in the ENGINE PERFORMANCE Section.
If no hard codes are found in self-diagnostics, proceed to TESTS W/O CODES article in the ENGINE PERFORMANCE Section for diagnosis
by symptom (i.e., ROUGH IDLE, NO START, etc.) or intermittent diagnostic procedures.
Terminal "D"Terminal "E"Terminal "C" Voltage
OpenOpenLess than one
GroundedOpenLess than 10
OpenGroundedGreater than 10
GroundedGroundedGreater than 10
ApplicationPrimary (Ohms)Secondary (Ohms)
1.3L & 1.6L0.8-1.66000-30,000
Copyr ight 2009 Mitchell Repair Information Company, LLC. All Rights Reserved.
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VANE AIR TEMPERATURE RESISTANCE (1)
WIDE OPEN THROTTLE SWITCH (1.3L)
This switch is part of the throttle position switch. See THROTTLE POSITION SWITCH (1.3L).
MODULES, RELAYS & SOLENOIDS
MODULES
Ignition Module
See IGNITION SYSTEM .
RELAYS
A/C Clutch Relay
See MISCELLANEOUS CONTROLS .
Cooling Fan Relay
See MISCELLANEOUS CONTROLS .
SOLENOIDS
Canister Purge Solenoid
See FUEL EVAPORATION .
Fuel Pressure Regulator Control Solenoid
See FUEL DELIVERY under FUEL SYSTEM.
Idle Speed Control (ISC) Solenoid
This solenoid is part of the Idle Speed Control By-Pass Air (ISC-BPA) valve. See IDLE CONTROL SYSTEM under FUEL SYSTEM.
FUEL SYSTEM
FUEL DELIVERY
Fuel Pressure Regulator
1. Measure fuel pressure. See FUEL PRESSURE in BASIC TESTING article in the ENGINE PERFORMANCE Section. Stop engine.
With fuel pressure tester still installed, measure fuel pressure after 5 minutes. If fuel pressure is greater than 21 psi (1.5 kg/cm
2 ) after 5
minutes, go to step 2). Replace fuel pressure regulator if fuel pressure does not remain higher than 21 psi (1.5 kg/cm
2 ).
2. Remove fuel pressure regulator. Inspect "O" ring, gasket and mounting surfaces for defects. Connect vacuum tester to fuel return tube,
and apply 20 in. Hg vacuum. Replace fuel pressure regulator if vacuum drops by more than 10 in. Hg in 10 seconds. Reinstall fuel
pressure regulator.
3. Again measure fuel pressure. If regulated fuel pressure is higher than specification, check for engine vacuum leaks, damage to fuel
pressure regulator housing or a restricted fuel return line. Replace fuel pressure regulator if no problems are found.
Fuel Pressure Regulator Control Solenoid (1.6L)
1. Locate PRESSURE CONTROL (PRC) solenoid on cowl panel next to canister purge solenoid. Unplug PRC connector. Remove both
vacuum lines. Plug one vacuum port and apply vacuum to remaining port. Replace PRC solenoid if it does not hold vacuum.
2. Connect 12-volt power to PRC terminals. If vacuum drops to zero, PRC solenoid is okay. Replace PRC solenoid if vacuum does not
drop to zero.
FUEL CONTROL
Fuel Injectors
1. Using stethoscope, listen for normal clicking sound at each injector during idle and acceleration. If clicking sound is not heard, remove
electrical connector from injector.
2. Using ohmmeter, measure resistance between injector terminals. See FUEL INJECTOR RESISTANCE
table. Replace injector if
°F (°C)Ohms
-4 (-20)15,000
32 (0)5200
68 (20)2500
104 (40)100
140 (60)600
176 (80)300
(1)Resistance may vary by plus or minus 15 percent
NOTE:For fuel pressure specifications, see FUEL PRESSURE SPECIFICAT IONS
article.
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Fig. 1: Testing Canister Purge Solenoid

Courtesy of FORD MOTOR CO.
Carbon Canister
1. Start and run engine until it is at operating temperature. Stop engine. Remove carbon canister. Carbon canister on 1.3L is located under
brake booster. Carbon canister is located in right side of engine compartment near cowl panel on 1.6L.
2. Inspect carbon canister for presence of liquid fuel, as evidenced by odor or weight. Blow into air vent and ensure air exits fro m fu el
vapor inlet. Replace carbon canister if it contains fuel, or if air does not pass freely through it.
POSITIVE CRANKCASE VENTILATION (PCV)
1. Remove PCV valve from valve cover and disconnect it from PCV h o se . S h a ke va l ve vigo r o u sl y t o e n su r e p l u n ge r is fr e e t o mo ve .
Replace PCV valve if plunger is not free.
2. Idle engine until it is warm. Remove fresh air hose at inlet end. Plug nipple immediately to prevent stalling. Verify presence of vacuum at
inlet end of hose. If vacuum is not present, replace PCV valve or service hoses or loose oil dipstick.
THROTTLE CONTROLS
Dashpot
Disconnect PCV valve. Remove resonance chamber. Push dashpot rod in and then release it. Replace dashpot if rod does not go in slowly and
return quickly.
MISCELLANEOUS CONTROLS
A/C CLUTCH
A/C Clutch Relay
Remove relay from its socket near left headlight, in front of battery. Connect ohmmeter to contact terminals (Blue/Red and Black/White wires
on mating connector). Ohmmeter should indicate continuity. Supply 12 volts to remaining terminals (Green/Yellow and Yellow wires on
mating connector). Ohmmeter should indicate no continuity.
COOLING FAN
Cooling Fan
Unplug connector from cooling fan. Apply 12 volts to one terminal of fan connector. Ground remaining fan connector terminal. Replace fan if
it does not run.
Cooling Fan Control Relay
Remove relay from its socket near left headlight. Connect ohmmeter to contact terminals. Wire colors are Yellow/Red and Black on mating
connector on Festiva; Yellow/Green and Black on Capri. Ohmmeter should indicate continuity. Supply 12 volts to remaining 2 relay
terminals. Ohmmeter should indicate no continuity.
NOTE:Although som e of the controlled devices listed here are not technically engine perform ance
com ponents, they can affect driveability if they m alfunction.
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Fig. 14: Identifying CANP Circuit & Connector
CANP CIRCUIT PIN IDENTIFICATION
1. Turn ignition off. Install BOB. Leave ECA disconnected. Turn ignition on. Remove canister purge hose from intake manifold, and apply
vacuum. Connect a jumper wire between CANP test terminal and ground. If vacuum releases, solenoid is okay. If vacuum does not
release, go to next step.
2. Locate CANP solenoid near center of cowl panel. Unplug solenoid connector. Apply vacuum to port from engine vacuum source.
Replace CANP solenoid if it does not hold vacuum.
3. Connect BOB. Leave ECA disconnected. Reconnect wiring to CANP solenoid. Turn ignition on. Apply vacuum to CANP solenoid.
Connect jumper wire between CANP test pin on BOB and ground. If vacuum drops to zero, solenoid function is okay. Return to QUIC
K
TESTS if sent here from there. If vacuum does not drop to zero, go to next step.
4. Turn ignition off. Unplug CANP solenoid connector. Turn ignition on. Measure voltage between VPWR wire on harness connector and
gr o u n d . If vo l t a ge is n o t h igh e r t h a n 1 0 vo l t s, r e p a ir VP WR wir e t o ma in r e l a y. If vo l t a ge is h igh e r t h a n 1 0 vo l t s, go t o n e xt step.
5. Turn ignition off. Unplug CANP solenoid connector. Turn ignition on. Measure voltage between solenoid connector VPWR wire and
solenoid connector SIG wire. Connect jumper wire between CANP test pin on BOB and ground. If voltage is higher than 10 volts only
when solenoid is activated, replace solenoid. If voltage is not higher than 10 volts only when solenoid is activated, go to next step.
6. Turn ignition off. Connect BOB. Leave ECA disconnected. Unplug CANP solenoid connector. Measure resistance between SIG test pin
and solenoid connector SIG wire. If resistance is not less than 5 ohms, repair SIG wire to ECA. If resistance is less than 5 ohms, go to
next step.
7. Turn ignition off. Connect BOB. Leave ECA disconnected. Unplug solenoid connector. Measure resistance between SIG test pin and all
other test pins. If resistance between SIG PRC test pin and any other pin is less than 5 ohms, repair CANP wire to ECA. If resistance
between CANP test pin and all other pins is greater than 10,000 ohms, replace ECA.
PINPOINT TEST ISC - IDLE SPEED CONTROL

Fig. 15: Identifying ISC Circuit & Connector

ISC CIRCUIT PIN IDENTIFICATION
1. Install BOB, leaving ECA disconnected. Turn ignition on. Connect a jumper between BOB test pin No. 41 and ground. Listen for
clicking sound from solenoid, mounted on throttle body. If clicking sound occurs, ISC solenoid is okay; return to QUICK TESTS if sen t
here from there. If no clicking sound occurs, go to next step.
2. Unplug ISC solenoid connector. With ignition on, measure voltage between VPWR wire and ground. If voltage is less than 10 volts,
repair VPWR wire to main relay. Go to next step if voltage is not less than 10 volts.
3. Measure voltage between ISC solenoid VPWR wire and solenoid connector SIG wire while cranking engine. Replace solenoid if voltage
is more than 10 volts only when engine is cranking. If okay, go to next step.
4. With BOB installed and ECA disconnected, unplug ISC solenoid connector. Check for continuity between BOB SIG test pin and ISC
connector SIG wire. If resistance is not less than 5 ohms, repair ISC wire between solenoid and ECA. If okay, go to next step.
5. With BOB installed and ECA disconnected, measure resistance between BOB SIG test pin and all other test pins. If resistance is less
than 5 ohms, repair short in SIC wire to ECA. If resistance is not less than 5 ohms, replace ECA.
PINPOINT TEST STI - SELF-TEST INPUT
STI CIRCUIT PIN IDENTIFICATION
CircuitECA PinBOB PinWire Color
CANP
1.3L2X31RED
1.6L2P32YEL
NOTE:Enter this test only when a Code 34 is displayed during QUICK T EST S procedure or when directed here
from another PINPOINT TEST.
CircuitECA PinBOB PinWire Color
ISC
1.3L2W41RED/BLK
1.6L2Q41GRN
NOTE:Enter this test only when sent here from QUICK TESTS.
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Fig. 17: Identifying VPWR Circuit & Connector

VPWR CIRCUIT PIN IDENTIFICATION
1. Turn ignition off. Install BOB, leaving ECA disconnected. Turn ignition on. Measure voltage between VPWR test pin and battery
gr o u n d . If vo l t a ge is n o t gr e a t e r t h a n 1 0 vo l t s, go t o st e p 3). If voltage is greater than 10 volts, go to next step.
2. Measure voltage between VPWR test pin and GROUND test pin. If voltage is greater than 10 volts, go to next step. Repeat measurement
for each ECA ground wire. If all voltages are greater than 10 volts, go to PINPOINT TEST VREF
. If all voltages are not greater than
10 volts, repair ECA ground wire in question.
3. Turn ignition off. Locate main power relay. On Capri, relay is located on left side of engine compartment. On Festiva, relay is located at
left front of engine compartment. Disconnect main power relay 4-wire connector. Using jumper wires, connect BATT, PWR, and GND
terminals of relay to corresponding trammels on connector. Leave VPWR wire disconnected.
4. Turn ignition on. Measure voltage between main power relay VPWR terminal (where VPWR wire was) and ground. If voltage is more
than 10 volts, repair VPWR circuit between main power relay and ECA. If voltage is not more than 10 volts, go to next step.
5. Unplug main relay connector. Measure voltage between harness connector BATT wire and ground. If voltage is not greater than 10
volts, repair BATT wire from battery to harness connector. If voltage is greater than 10 volts, go to next step.
6. Unplug main relay connector. Measure voltage between harness connector PWR wire and ground. If voltage is not greater than 10 volts,
repair PWR wire from ignition switch to harness connector. If voltage is greater than 10 volts, go to next step.
7. Measure voltage between main power relay BATT wire and main power relay GROUND wire. If voltage is less than 10 volts, repair
main power relay ground wire. If voltage is not less than 10 volts, ground circuit is okay; replace main power relay.
PINPOINT TEST VREF - REFERENCE VOLTAGE & SIGNAL RETURN
CircuitECA PinBOB PinWire Color
1.3L
GND2A39, 40, 44, 60BLK
GND2B20BLK
GND2C16BLK
VPWR1B37, 57YEL/BLK
1.6L
GND2R49BLK
GND3A20BLK
GND3G40BLK
VPWR3I37YEL/GRN
NOTE:Enter this test only when directed from another PINPOINT T EST .
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Back To Article
H - T EST S W/O CODES
1991-92 ENGINE PERFORMANCE Ford Motor Co. T rouble Shooting - No Codes
INTRODUCTION
Before diagnosing symptoms or intermittent faults, perform steps in BASIC TESTING and TESTS W/CODES articles in the ENGINE
PERFORMANCE Section. Use this article to diagnose driveability problems existing when a hard fault code is not present or vehicle is not
equipped with a self-diagnostic system.
Symptom checks can direct the technician to malfunctioning component(s) for further diagnosis. A symptom should lead to a specific
component, system test or adjustment.
Use intermittent test procedures to locate driveability problems which DO NOT occur when the vehicle is being tested. These test procedures
should also be used if a soft (intermittent) trouble code was present but no problem was found during self-diagnostic testing.
SYMPTOMS
SYMPTOM DIAGNOSIS
Symptom checks cannot be used properly unless problem occurs while vehicle is being tested. To reduce diagnostic time, ensure steps in
BASIC TESTING and TESTS W/CODES articles in the ENGINE PERFORMANCE Section were performed before diagnosing a symptom.
These symptoms are available for diagnosis.
Backfire through induction or exhaust.
Dieseling (run-on).
Lack of power.
Spark knock (pinging).
Stalls/quits.
Stumble/hesitation during acceleration.
Misses/surges.
Idle is fast/slow return to idle.
Id l e is ro u gh .
Engine speeds up.
Cranks normally/no start.
Cranks normally/slow to start.
Poor fuel economy.
Exhaust smoke/odor.
Fuel odor/leaks.
Fails emission test.
BACKFIRE THROUGH INDUCTION OR EXHAUST
Check vane airflow meter.
Check idle speed control solenoid.
DIESELING (RUN-ON)
Check idle speed control solenoid.
LACK OF POWER
Check vane airflow meter.
Check throttle position switch.
Check heated exhaust gas oxygen sensor.
Check A/C switch.
Check wide open throttle A/C (WAC) relay.
SPARK KNOCK (PINGING)
Verify ignition timing is correct.
Check vane airflow meter.
STALLS/QUITS NOTE:Som e driveability problem s m ay have been corrected by m anufacturer with a revised com puter
calibration chip or com puter control unit. Check with m anufacturer for latest chip or com puter
application.
NOTE:For specific testing procedures, see SYST EM/COMPONENT T EST S article in the ENGINE
PERFORMANCE Section. For specifications, see ADJUST MENT S or SPECIFICAT IONS article in the
ENGINE PERFORMANCE Section.
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Check vane airflow meter.
Check idle speed control solenoid.
Check pressure regulator control solenoid.
Check heated exhaust gas oxygen sensor.
Check engine coolant temperature sensor.
Check A/C load control solenoid.
STUMBLE/HESITATION DURING ACCELERATION
Check throttle position switch.
Check vane airflow meter.
Check canister purge solenoid.
Check heated exhaust gas oxygen sensor.
Check wide open throttle A/C (WAC) relay.
Check A/C thermostatic switch.
MISSES/SURGES
Check exhaust gas oxygen sensor.
Check throttle position switch.
Check vane airflow meter.
Check wide open throttle vacuum switch.
Check A/C load control solenoid.
Check engine coolant temperature sensor.
IDLE IS FAST/SLOW RETURN TO IDLE
Check idle speed control solenoid.
Check by-pass air control valve.
Check engine coolant temperature sensor.
Check A/C load control solenoid.
IDLE IS ROUGH
Check idle speed control solenoid.
Check A/C load control solenoid.
Check by-pass air control valve.
Check throttle position switch.
Check vane airflow meter.
Check vane air temperature sensor.
Check canister purge solenoid.
Check engine cooling fan.
Check headlight switch.
Check blower control switch.
Check A/C thermostatic switch.
Check neutral safety switch.
Check neutral gear switch or clutch engage switch.
Check heated exhaust gas oxygen sensor.
ENGINE SPEEDS UP
Check idle speed control solenoid.
Check heated exhaust gas oxygen sensor.
Check by-pass air control valve.
CRANKS NORMALLY/NO START
Verify secondary ignition spark is present.
Verify fuel pressure is within specification.
Check vane airflow meter.
Check engine coolant temperature sensor.
CRANKS NORMALLY/SLOW TO START
Check ignition module.
Check engine coolant temperature sensor.
Check vane airflow meter.
Check evaporative emission control components.
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FUEL DELIVERY SYSTEM
Major components of the fuel delivery system are an electric fuel pump, fuel supply and return lines, a pressure regulator, fuel rail and fuel
injectors. See Fig. 2
or Fig. 3 .

Fig. 2: Locating Fuel Delivery System Components (Festiva)

Courtesy of FORD MOTOR CO.

Fig. 3: Locating Fuel Delivery System Components (Capri)

Courtesy of FORD MOTOR CO.
FUEL PUMP
The fuel pump, located inside the fuel tank, includes a check valve at the outlet and a filter element at the inlet. A pressure relief valve limits
maximu m fu el o u t l et p ressu re.
FUEL PUMP RELAY
This relay prevents fuel pump operation unless the engine is cranking or when a signal from the VAF confirms the engine is running. See Fig.
4 . Internal circuitry holds the relay contacts closed during momentary loss of the VAF signal during rapid deceleration. The fuel pump relay is
Page 3 of 6 MITCHELL 1 ARTICLE - E - THEORY/OPERATION 1991 ENGINE PERFORMANCE Ford/Mercury Theory & Operation
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VCRM
Variable Control Relay Module
VIN
Vehicle Identification Number
VM
Vacuum Modulator
Volt.
Voltage
VOM
Volt-Ohmmeter (Analog)
VRV
Vacuum Regulator Valve
VSS
Vehicle Speed Sensor
VSV
Vacuum Switching Valve
"W"
W/
With
W/O
Without
WAC
Wide Open Throttle A/C Switch
WOT
Wide Open Throttle
Copyr ight 2009 Mitchell Repair Information Company, LLC. All Rights Reserved.
Article GUID: A00002370
Page 15 of 15 MITCHELL 1 ARTICLE - GENERAL INFORMATION Commonly Used Abbreviations
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