1991 FORD FESTIVA ECU

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A/C SYST EM PRECAUT IONS
A/C GENERAL SERVICING A/C System Servicing cautions
BEFORE OPENING THE SYSTEM
Before disconnecting any lines or fittings, the system must be completely discharged using approved refrigerant recovery/recycling equipment.
DISCHARGING A/C SYSTEM
1. Remove service valve caps and install gauges. For high side gauge hose, Adapter (D81L-19703-A) must be used to connect to high side
service valve.
2. Place open end of center hose in garage exhaust outlet or in a well ventilated area. Slightly open low side gauge valve and let refrigerant
escape slowly without loosing refrigerant oil.
3. When system is nearly discharged, using approved refrigerant recovery/recycling equipment, open high side gauge valve to release any
pressure trapped in compressor. Close valves immediately after discharging to prevent entry of moisture.
DISCONNECTING LINES & FITTINGS
1. After system is discharged, using approved refrigerant recovery/recycling equipment, carefully clean entire area around coupling nut to
prevent dirt entering system. Always use two wrenches to avoid twisting or distorting lines and fittings (hold fitting with one wrench
while loosening coupling nut with second wrench).
2. Ford spring-coupling fittings require a special coupling tool (Motorcraft YT-1056) to open or close. See procedure under Connecting
Lines and Fittings.
3. Cap or plug all LINES and FITTINGS immediately to prevent entry of air and moisture into system. Do not remove these caps until
connections are being made.
COMPONENT REPLACEMENT
When components are replaced, system oil level must be adjusted. Add refrigeration oil to replacement component. See Compressor oil Check
article, as well as COMPONENT OIL REPLACEMENT QUANTITIES chart under A/C SYSTEM SPECS article in this section.
USING R-12 REFRIGERANT - SAFETY PRECAUTIONS
1. Always work in a well-ventilated, clean area. Refrigerant (R-12) is heavier than oxygen, and will displace oxygen in a confined area.
Always wear eye protection when working around air conditioning systems and R-12. The system's high pressure can cause severe injury
to eyes and skin if a hose were to burst. R-12 evaporates quickly when exposed to atmosphere, freezing anything it contacts.
2. Use care when handling refrigerant containers. DO NOT drop or strike containers or expose refrigerant containers to excessive heat.
Containers must never be heated more than 125°F (52°C). Never expose R-12 directly to open flame.
USING INDIVIDUAL R-12 CANS
Disposable refrigerant cans (referred to as one pound cans) have a flat type seal or a screw type seal, and proper can tap must be used for each
type. Be sure sealing gasket on can tap is in good condition. A proper safety can tap will prevent refrigerant from flowing back into open can,
as tap has a one-way flow control.
MULTI-CAN DISPENSING VALVES
A multi-can dispensing valve allows attachment of several cans of refrigerant, and is a good substitute when a bulk container is not available.
Cans are installed onto each leg of multi-can dispensing valve in the same manner as the individual cans, and each leg has its own can tap.
CAN TAP INSTALLATION FLAT TYPE SEAL CANS
On cam-lock or one-piece can taps, first turn the handle outward to the fully open position. Securely engage locking lugs over the can flange,
and lock them in place by turning cam lock or locking nut. Screw tap assembly into adapter so sealing gasket is fully seated against the can
top. Turn tap inward to pierce the can and close the tap. DO NOT open tap until ready to purge the service hose or dispense refrigerant into
the system.
On 2-piece can taps, be certain tap handle is turned fully inward to the closed position. Check that locking base is turned to its outer limit.
Securely engage locking lugs over the can flange. Turn entire tap assembly (without disturbing the closed setting) downward into the locking
base to pierce the can. DO NOT open tap until ready to dispense into system. CAUT ION: When discharging air conditioning system , use only approved refrigerant recovery/recycling
equipm ent. Make every attem pt to avoid discharging refrigerant into the atm osphere.
NOTE:Recent findings by the EPA indicate that R-11, R-12 and R-113 are harm ful to the Earths' protective
Ozone layer. Make every attem pt possible, to avoid discharging R-11, R-12 or R-113 into the
atm osphere.
CAUT ION: When R-12 is exposed to an open flam e, drawn into a running engine, or detected with a Halide
(propane) leak tester, poisonous phosgene gas is form ed. Keep work areas ventilated and avoid
running engines near work area.
NOTE:Recent findings by the EPA indicate that refrigerant is harm ful to the Earth's protective Ozone layer.
When discharging refrigerant avoid allowing refrigerant to enter the atm osphere. Refrigerant recovery
system should be used when discharging the system .
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SCREW TYPE SEAL CANS
Ensure can tap is fully closed. Screw refrigerant can into can tap fitting until tight. This will pierce the can. Connect tap to center hose on
manifold gauge set. DO NOT open tap until ready to dispense R-12 into system.
CONNECTING LINES & FITTINGS
1. A new "O" ring should be used in all instances when connecting lines and fittings (dip "O" ring in clean refrigeration oil and make
certain it is not twisted during installation). Always use two wrenches to avoid twisting or distorting lines and fittings, tighten coupling
nuts securely.
2. Ford spring-coupling fittings require a special coupling tool (Motorcraft YT-1056) to open or close. Use the following procedure to
connect or disconnect the spring-coupling fitting.
Ford Spring-Coupling Fitting
1. Discharge system using approved refrigerant recovery/recycling equipment. Place proper end of tool over refrigerant line. Tool fits both
3/8" and 1/2" fittings. Push tool into fitting cage to release spring inside. Pull lines apart and remove tool.
2. Before connecting, check internal spring for damage. If necessary, pry spring out and replace it. Clean fittings and install new "O" rings.

Fig. 1: Assembling Ford Spring
-Coupling Fitting
PLACING SYSTEM IN OPERATION
After component replacement and/or system servicing has been completed and all connections have been made, proceed as follows:
1. Evacuate the system using a vacuum pump.
2. Charge the system with new R-12 (refrigerant) according to each individual vehicle as outlined in the GENERAL SERVICING article.
Also see Refrigerant Capacity in this Section.
3. Leak test the system, with particular attention to all new connections and components.
4. Make a performance test of the system. Never assume that a recharging has automatically corrected a problem.
COMPRESSOR REMOVAL INFORMATION - ISOLATION METHOD
On systems which have compressors equipped with stem-type service valves (Tecumseh), it is possible to isolate the compressor for removal.
Isolating
Turn both high and low pressure manual valves to extreme clockwise (front seat) position. Loosen cap on high pressure manual valve
connection to compressor and allow gas to escape until compressor is relieved of pressure.
COMPRESSOR REMOVAL INFORMATION-DISCHARGE METHOD
This procedure is to be used on vehicles which have compressor equipped with Schrader service valves. In these cases, the compressor cannot
be isolated and the system must be discharged, using approved refrigerant recovery/recycling equipment, prior to compressor removal. WARNING:DO NOT open high side hand valve while air conditioning system is in operation. T his high pressure
could rupture can or fitting at safety can valve, resulting in dam age and personal injury.
CAUT ION: Use ONLY "O" rings designed for these Ford fittings (Motorcraft YF-982). Norm al refrigerant "O" rings
will NOT seal.
Copyr ight 2009 Mitchell Repair Information Company, LLC. All Rights Reserved.
Article GUID: A00039191
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5. Check blower motor fan switch continuity. Resistance should not exceed 4 ohms. See BLOWER MOTOR FAN SWITCH
CONTINUITY table. If continuity is not present, replace fan switch. If continuity is okay, repair open in Black wire from blower motor
switch to ground.
BLOWER MOTOR FAN SWITCH CONTINUITY
REMOVAL & INSTALLATION
CONTROL PANEL
1. Remove bezel screws and accessory bezel. Remove radio. Remove 4 screws securing control panel to instrument panel. Remove glove
box attaching screws and glove box. Remove the retaining clip and disconnect fresh/recirculation air door cable from mode door lever.
2. Disconnect mode select cable at mode control door lever. Disconnect temperature control cable at temperature control mode door lever.
Pull control panel away from instrument panel. Disconnect blower motor switch connector. Disconnect illumination electrical
connector. Remove control panel. To install, reverse removal procedure. Adjust control cables. See ADJUSTMENTS in this article.
BLOWER MOTOR FAN SWITCH
Remove control panel. See CONTROL PANEL R & I
. Remove blower motor fan switch knob. Remove attaching nut. To install, reverse
removal procedure.
HEATER CORE
1. Disconnect negative battery cable. Remove steering wheel by prying out center trim insert and removing steering wheel retaining nut.
Remove 2 steering wheel cover retaining screws and remove cover. Using a steering wheel puller, remove steering wheel.
2. Remove 5 screws and remove lower and upper steering column covers. Disconnect electrical connections and remove multifunction
switch. Remove 5 screws and pull instrument cluster hood rearward. Disconnect electrical connections and remove instrument cluster
hood.
3. Disconnect speedometer cable at transaxle. Remove 4 instrument cluster screws. Pull instrument cluster rearward and disconnect
speedometer cable and electrical connections. Remove instrument cluster.
4. Remove 2 center bracket mounting bolts under steering column and remove bracket. Remove glove box attaching screws and remove
glove box. Remove left and right heater ducts. Remove fuse panel cover. Remove 2 screws securing fuse panel and push fuse panel
inward. DO NOT remove fuse panel.
5. Slide both seats to most forward position. Remove 2 console attaching screws, located in front of seat belt anchors. Slide both seats to
rearmost position. Remove parking brake console insert. Using a Phillips screwdriver, remove push retainer insert, located at front lower
edge of parking brake console. Pull back on parking brake lever and remove parking brake console.
6. Remove gearshift knob. Remove screws and remove shift console. Remove radio/heater control panel bezel screws and remove bezel.
Remove 4 radio attaching screws. Pull radio out and disconnect antenna lead and electrical connections. Disconnect radio ground lead
and remove radio.
7. Remove 4 screws attaching heater control panel. Disconnect control cables and electrical connections. Remove control panel, while
pulling cables through opening.
8. Pry out bolt cover trim inserts in top corners of dash. Remove bolts located under trim panels. Remove 7 instrument panel attaching
bolts and 2 nuts. Pull instrument panel rearward. Disconnect any harness connectors and clips. Remove instrument panel.
9. Disconnect electrical connections at blower and resistor. Remove harness from routing brackets on heater box. Loosen clamp screw
securing air inlet housing. Remove attaching nuts at top and bottom of heater box. Disconnect defroster ducts and remove heater
assembly.
10. Disconnect link connecting 2 defroster doors. Remove attaching screw just above and to right of blower resistor. Turn heater assembly
around and remove screw just to left of blower motor opening. Remove clips securing 2 halves of heater assembly. Separate halves. Lift
out heater core.
11. To install, reverse removal procedure. Ensure all heater control cables are routed and adjusted properly. See ADJUSTMENTS in this
article. Fill cooling system. Check for leaks.
BLOWER MOTOR & RESISTOR
Disconnect negative battery cable. Remove instrument panel spacer brace located below steering column. Remove airflow duct below steering
column. Disconnect blower motor or resistor wiring. Remove 3 blower motor attaching screws or 2 resistor attaching screws and remove
component. To install, reverse removal procedure.
Switch PositionContinuity Between Wire Colors
1Black-to-Blue/White
2Black-to-Blue/Yellow & Blue/Yellow-to-Blue/Red
3Black-to-Blue/Black & Blue/Black-to-Blue/Red
Page 2 of 4 MITCHELL 1 ARTICLE - HEATER SYSTEM 1990-92 HEATER SYSTEMS Ford Motor Co.
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Fig. 3: Cross
-Sectional View of Thermostatic Expansion Valve
Courtesy of FORD MOTOR CO.
ADJUSTMENTS
TEMPERATURE CONTROL CABLE
Temperature control cable is located at left base of evaporator housing. See Fig. 4
. Release cable retaining clip. Position temperature control
knob in maximum cool position. While holding thermostat cable in maximum cool position, secure cable casing using retaining clip.
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Fig. 4: Adjusting Temperature Control Cable

Courtesy of FORD MOTOR CO.
RECIRCULATED/FRESH AIR DOOR CABLE
Remove glove box retaining screws and glove box. Release cable retaining clip. See Fig. 5
. Move control knob to recirculation position. Hold
door lever in recirculation position, and secure cable casing using retaining clip. Install glove box.

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Fig. 5: Adjusting Recirculated/Fresh Air Door Cable
Courtesy of FORD MOTOR CO.
MODE SELECTOR CABLE
1. Remove air distribution plenum and instrument panel brace. See AIR DISTRIBUTION PLENUM
under REMOVAL &
INSTALLATION. Release cable retaining clip. See Fig. 6
.
2. Move control knob to vent position. While holding lever downward against stop, secure cable using retaining clip.
3. Disconnect defrost door link at defrost door lever. While holding defrost door upward against its stop, adjust defrost door link to a free
fit in defrost door lever. Install air distribution duct. Install instrument panel brace.

Fig. 6: Adjusting Mode Select Cable

Courtesy of FORD MOTOR CO.
TROUBLE SHOOTING
COMPRESSOR CLUTCH TROUBLE CHARTS

Fig. 7: Compressor Clutch Trouble Chart CC1

Courtesy of FORD MOTOR CO.
NOTE:Use the following trouble shooting charts to diagnose air conditioning system problem s.
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Fig. 29: Condensor Fan Trouble Chart CF9

Courtesy of FORD MOTOR CO.
REMOVAL & INSTALLATION
COMPRESSOR
Removal & Installation
1. Discharge A/C system using approved refrigerant recovery/recycling equipment. Disconnect negative battery cable. Remove compressor
drive belt. Disconnect electrical connector. Disconnect refrigerant lines, and plug openings.
2. Remove compressor mounting bolts and compressor. See Fig. 1
. To install, reverse removal procedure. If installing a new compressor,
drain 1.2 ounces of refrigerant oil from compressor before installation. Evacuate and recharge system.
CONDENSER
Removal & Installation
1. Discharge A/C system using approved refrigerant recovery/recycling equipment. Remove radiator grille. Remove right-side sight glass
cover. Disconnect refrigerant line from receiver-drier. Remove refrigerant line clamp from condenser bracket. Remove hood latch and
center brace bolts.
2. Remove condenser fan (if equipped). Remove condenser mounting bolts. Lift out condenser and mounting grommets. See Fig. 1
. To
install, reverse removal procedure. Ensure mounting grommets are properly positioned. Install new "O" rings on all refrigerant line.
Evacuate and recharge system.
RECEIVER-DRIER
Removal & Installation
Discharge A/C system using approved refrigerant recovery/recycling equipment. Remove condenser. See CONDENSER under REMOVAL &
INSTALLATION. Disconnect refrigerant lines from receiver-drier, and plug openings immediately. Remove receiver-drier mounting bolts and
receiver-drier. See Fig. 1
. To install, reverse removal procedure. Use new "O" rings. Evacuate and recharge system.
EVAPORATOR HOUSING
Removal & Installation
1. Disconnect negative battery cable. Discharge A/C system using approved refrigerant recovery/recycling equipment. Disconnect
evaporator outlet tubes (refrigerant lines), and plug openings. See Fig. 1
. Remove glove box. Disconnect 2 electrical connectors from
thermostatic switch.
2. Disconnect temperature control cable. See Fig. 4
. Remove wiring harness clamps from evaporator housing. Loosen clamp screws
securing connector duct to evaporator housing. Remove evaporator drain hose. Remove air inlet duct. See Fig. 2
.
3. Remove evaporator housing-to-dash panel bolts. Remove evaporator housing. To install, reverse removal procedure. Use new "O" rings.
Evacuate and recharge system.
EVAPORATOR
Removal & Installation
1. Remove evaporator housing. See EVAPORATOR HOUSING under REMOVAL & INSTALLATION. See Fig. 1 . Remove upper and
lower evaporator case half clips. Remove upper housing. Carefully pull sensing tube from evaporator core fins while removing
thermostat. Remove evaporator from lower housing. Remove stand-off insert from between inlet and outlet tubes.
2. Remove insulator from around capillary tube and thermostatic expansion valve. Remove capillary tube-to-suction tube clamp.
Disconnect evaporator tube fitting and thermostatic expansion valve. To install, reverse removal procedure. Use new "O" rings on all
refrigerant line connections. Evacuate and recharge system.
THERMOSTATIC SW ITCH
Removal & Installation
Remove evaporator housing. See EVAPORATOR HOUSING under REMOVAL & INSTALLATION. See Fig. 1. Remove 10 clips retaining
evaporator housing halves. Remove upper housing section. Remove thermostatic switch mounting screws. Carefully pull thermostat sensing
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BRAKE PAD WEAR INDICATOR
CATALYTIC CONVERTER
COOLANT (PROPYLENE-GLYCOL FORMULATIONS)
ELECTROSTATIC DISCHARGE SENSITIVE (ESD) PARTS
ENGINE OIL
FUEL PUMP SHUTOFF SWITCH
This switch stops flow of fuel to engine after a collision. The impact does not have to be great for switch to be triggered. Switch must be reset
after collision. Switch is located under left rear speaker in luggage compartment. Press button to reset switch.
FUEL SYSTEM SERVICE
HALOGEN BULBS
PASSIVE RESTRAINTS
RADIATOR CAP
RADIATOR FAN
WARRANTY INFORMATION
BASIC NEW CAR LIMITED WARRANTY
All parts of the vehicle, except tires, are covered against defects in factory-supplied materials and workmanship for 12 months or 12,000 miles, CAUT ION: Indicator will cause a squealing or scraping noise, warning that brake pads need replacem ent.
CAUT ION: Continued operation of vehicle with a severe m alfunction could cause converter to overheat, resulting
in possible dam age to converter and vehicle.
CAUT ION: T o avoid possible dam age to vehicle use only ethylene-glycol based coolants with a m ixture ratio from
44-68% anti-freeze. DO NOT use 100% anti-freeze as it will cause the form ation of cooling system
deposits. T his results in coolant tem peratures of over 300° F (149°C) which can m elt plastics. 100% anti-
freeze has a freeze point of only -8° F (-22°C).
CAUT ION: Propylene-Glycol Mixtures has a sm aller tem perature range than Ethylene-Glycol. T he tem perature
range (freeze-boil) of a 50/50 Anti-Freeze/Water Mix is as follows: Propylene-Glycol -26° F (-32°C) - 257° F
(125°C) Ethylene-Glycol -35° F (-37°C) - 263° F (128°C)
CAUT ION: Propylene-Glycol/Ethylene-Glycol Mixtures can cause the destabilization of various corrosion inhibitors.
Also Propylene-Glycol/Ethylene-Glycol has a different specific gravity than Ethylene-Glycol coolant,
which will result in inaccurate freeze point calculations.
WARNING:Many solid state electrical com ponents can be dam aged by static electricity (ESD). Som e will display a
warning label, but m any will not. Discharge personal static electricity by touching a m etal ground point
on the vehicle prior to servicing any ESD sensitive com ponent.
CAUT ION: Never use non-detergent or straight m ineral oil.
WARNING:Relieve fuel system pressure prior to servicing any fuel system com ponent (fuel injection m odels).
WARNING:Halogen bulbs contain pressurized gas which m ay explode if overheated. DO NOT touch glass portion
of bulb with bare hands. Eye protection should be worn when handling or working around halogen
bulbs.
CAUT ION: Before operating vehicle, securely fasten passive shoulder restraints to the em ergency release buckles.
T he buckle fits in only one way. Ensure to position it properly.
CAUT ION: Always disconnect the fan m otor when working near the radiator fan. T he fan is tem perature controlled
and could start at any tim e even when the ignition key is in the OFF position. DO NOT loosen or rem ove
radiator cap when cooling system is hot.
WARNING:Keep hands away from radiator fan. Fan is controlled by a therm ostatic switch which m ay com e on or
run for up to 15 m inutes even after engine is turned off.
CAUT ION: Due to the different warranties offered in various regions and the variety of after-m arket extended
warranties available, please refer to the warranty package that cam e with the vehicle to verify all
warranty options.
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