
TURBO BOOST GAUGE & SENSOR (CAPRI)
1. Disconnect 3-pin boost sensor electrical connected located on right side of firewall. Turn ignition on. Measure voltage between
Yellow/Green and Black wires. Voltage should be greater than 10 volts. Turn ignition off. If voltage is greater than 10 volts, go t o n e xt
step. If voltage is 10 volts or less, repair Yellow/Green or Black wires as necessary.
2. Remove instrument panel. See INSTRUMENT PANEL
under REMOVAL & INSTALLATION. Disconnect instrument panel 8-pin
connector. With boost sensor disconnected, measure resistance through White/Black between instrument panel and boost sensor harness
connector. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair or replace White/Black wire.
3. With 8-pin instrument panel connector disconnected, ground White/Black at boost gauge. Boost gauge should read low. Apply 12 vo l t s
to White/Black wire at boost gauge. Boost gauge should read high. If boost gauge operates as specified, go to next step. If boost gauge
does not operate as specified, replace boost gauge.
4. Reconnect instrument panel connectors (if removed). With ignition on and boost sensor disconnected, install jumper wire between
Yellow/Green and White/Black wires of boost sensor vehicle harness connector. Boost gauge should read high. If boost gauge reads
high, replace boost sensor. If boost gauge does not read high, go to TROUBLE SHOOTING
for other possible causes.
REMOVAL & INSTALLATION
INSTRUMENT PANEL
Removal & Installation (Capri)
1. Disconnect negative battery cable. Pull storage compartment from heater/radio bezel. Pull outward and remove trim covers located on
both sides of steering column. Remove retaining screws and carefully pull instrument panel bezel partially away from dash. Disconnect
electrical connectors from clock and switches in bezel. Remove instrument panel bezel.
2. Disconnect speedometer cable from transaxle. Remove instrument panel retaining screws and slide instrument panel outward. Press lock
tab and release speedometer cable from instrument panel. Remove electrical connectors from rear of instrument panel. Remove
instrument panel. To install instrument panel, reverse removal procedure.
Removal & Installation (Festiva)
1. Disconnect negative battery cable. Remove upper and lower steering column covers. Remove screws from panel bezel and remove bezel.
Disconnect rear wiper switch and rear defogger switch wiring harness connectors (if equipped).
2. Remove instrument panel-to-dash screws. Pull panel from dash. Reach behind panel and release speedometer drive cable lock tab. Lift
lock tabs and disconnect 2 electrical connectors from rear of panel. Remove panel. To install instrument panel, reverse removal
procedure.
INDICATOR LIGHTS
Removal & Installation
Remove instrument panel for access to indicator light bulbs. See INSTRUMENT PANEL under REMOVAL & INSTALLATION. To remove
bulb, rotate bulb counterclockwise to disengage locking tabs. When tabs release, pull bulb from printed circuit board. To install bulb, reverse
removal procedure. Install instrument panel and test lights.
SPEEDOMETER R & I
Removal & Installation (Capri)
R e mo ve n e ga t ive b a t t e r y c a b l e . R e mo ve in st r u me n t p a n e l . S e e INSTRUMENT PANEL under REMOVAL & INSTALLATION. Disassemble
instrument panel and remove speedometer/tachometer/boost gauge assembly from instrument panel. To install, apply a 3/16" (4.6 mm) b al l o f
Silicone Damping Grease (D7AZ-19A331-A) into drive hole of speedometer head. Reverse removal procedure to complete installation.
Removal & Installation (Festiva)
R e mo ve n e ga t ive b a t t e r y c a b l e . R e mo ve in st r u me n t p a n e l . S e e INSTRUMENT PANEL under REMOVAL & INSTALLATION. Disassemble
instrument panel and remove speedometer head assembly from instrument panel. Speedometer is a separate module and can be removed
independently from gauges. To install, reverse removal procedure.
SPEED SENSOR
On vehicles equipped with speed control, a speed sensor is mounted in speedometer head assembly. If replacement is necessary, speedometer
head assembly must be replaced. See SPEEDOMETER R & I
under REMOVAL & INSTALLATION.
FUEL GAUGE
Removal & Installation
Remo ve in st ru men t p an el . See INSTRUMENT PANEL under REMOVAL & INSTALLATION. Disassemble panel and remove fuel gauge.
To install gauge, reverse removal procedure. On Capri, the fuel/volt gauge must be replaced as an assembly.
FUEL SENDING UNIT
Removal & Installation
1. For Festiva, remove rear seat. For Capri, remove rear seat cushion. On Festiva, remove carpet hold-down pins and lift carpet for access
to sending unit access plate. On all models, remove access plate screws. NOTE:Federal law requires that a label stating the odom eter has been repaired or replaced be affixed to any
vehicle that has its odom eter repaired, replaced or set to zero.
Page 4 of 5 MITCHELL 1 ARTICLE - INSTRUMENT PANEL 1991 ACCESSORIES & SAFETY EQUIPMENT Ford Motor Co. Switches
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1991 GENERAL SERVICING
A/C Com pressor Refrigerant Oil Checking
ISOLATING COMPRESSOR
1. Connect service gauge set to the compressor service valves and open compressor valves slightly (turn in clockwise). Start engine and
operate air conditioning. Slowly turn compressor suction valve clockwise toward closed (front-seated) position.
2. When suction pressure is reduced to zero or less, turn off engine and compressor and quickly turn suction valve stem in to full front-
seated position. Suction pressure should be slightly above zero. Turn discharge valve into front-seated position.
3. To check oil level, slowly open compressor crankcase plug to relieve any remaining pressure. After oil level is corrected, cap service
gauge ports on both valves. Back-seat suction service valve to allow refrigerant to enter compressor. Open discharge valve halfway.
4. Loosen discharge service valve cap, allowing refrigerant pressure to force air out of compressor. Back-seat service valve and tighten cap.
Compressor is now ready for operation.
REFRIGERANT OIL
Only new, pure, moisture-free refrigerant oil should be used in the air conditioning system. This oil is highly refined and dehydrated to a point
where moisture content is less than 10 parts per million. The oil container must be tightly closed at all times when not in use, or moisture will
be absorbed into the refrigerant oil from the air.
SERVICING PRECAUTIONS
DISCHARGING SYSTEM PRECAUTIONS
If compressor has stem-type service valves, it can be isolated and removed without discharging entire system. See ISOLATING
COMPRESSOR at the beginning of this article. Otherwise, discharge system completely before loosening any fittings.
DISCONNECTING LINES & FITTINGS TEST
After system is discharged, carefully clean area around all fittings to be opened. Always use 2 wrenches when tightening or loosening fittings
to avoid twisting or distorting lines. Cap or plug all openings as soon as lines are removed. DO NOT remove caps until immediately before
connections are made. This will keep entry of air and moisture to a minimum.
CONNECTING LINES AND FITTINGS
A new gasket or "O" ring should be used in all instances when connecting lines or fittings. Dip "O" ring in new refrigerant oil and ensure it is
not twisted during installation. Always use 2 wrenches to prevent damage to lines and fittings.
PLACING SYSTEM IN OPERATION
After component service or replacement has been completed and all connections have been made, evacuate system thoroughly with a vacuum
pump. Charge system with proper amount of refrigerant and perform a leak test. See REFRIGERANT OIL & R-12 SPECIFICATIONS chart in
this section for system capacities. Be sure to check all fittings that have been opened. After system has been leak tested, make a system
performance check.
ATSUGI ROTARY VANE DRAIN & REFILL
1. Before checking and adjusting oil level, operate compressor at engine idling speed, with controls set for maximum cooling and high
blower speed, for 20 to 30 minutes to return oil to compressor.
2. Stop engine, discharge refrigerant and remove compressor from vehicle. See SERVICING PRECAUTIONS at beginning of article. Drain
compressor oil from compressor discharge port and measure the amount. Oil is sometimes hard to drain when compressor is cool.
Remove oil while compressor is warm.
3. If the amount drained is less than 3 ounces, conduct leak tests at system connections, and if necessary, repair or replace faulty parts.
Check purity of oil and adjust oil level as follows.
4. If amount drained was above 3 ounces, oil level is right. Pour in same amount as was drained. If amount drained was below 3 ounces,
pour in 3 ounces of new refrigerant oil.
BOSCH 6-CYL DRAIN & REFILL
1. Before checking and adjusting oil level, operate compressor at engine idling speed, with controls set for maximum cooling and high
blower speed, for 20 to 30 minutes to return oil to compressor.
2. Stop engine and discharge refrigerant. Remove refrigerant oil level inspection plug on side of compressor. Oil should be at lower lip of
threaded hole. Add necessary new refrigerant oil (if low). Replace inspection plug and tighten to 10-12 ft. lbs. (14-16 N.m). NOTE:Only com pressors with stem -type service valves can be isolated.
NOTE:Recent findings by the EPA indicate that refrigerant is harm ful to the earth's protective Ozone layer.
When discharging refrigerant, DO NOT allow refrigerant to enter the atm osphere. If available, use
refrigerant recovery/recycle system s when discharging system . Always follow m anufacturer's
instructions.
NOTE:Air conditioning system s will not norm ally need addition of refrigerant oil unless definite oil loss has
occurred due to ruptured lines, leaking com pressor seals, com pressor overhaul or com ponent
replacem ent.
Page 1 of 4 MITCHELL 1 ARTICLE - 1991 GENERAL SERVICING A/C Compressor Refrigerant Oil Checking
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A/C COMPRESSOR SERVICING
1991 GENERAL SERVICING Com pressor Service
ISOLATING COMPRESSOR
1. Connect service gauge set to the compressor service valves and open compressor valves slightly (turn in clockwise). Start engine and
operate air conditioning. Slowly turn compressor suction valve clockwise toward closed (front-seated) position.
2. When suction pressure is reduced to zero or less, turn off engine and compressor and quickly turn suction valve stem in to full front-
seated position. Suction pressure should be slightly above zero. Turn discharge valve into front-seated position.
3. To check oil level, slowly open compressor crankcase plug to relieve any remaining pressure. After oil level is corrected, cap service
gauge ports on both valves. Back-seat suction service valve to allow refrigerant to enter compressor. Open discharge valve halfway.
4. Loosen discharge service valve cap, allowing refrigerant pressure to force air out of compressor. Back-seat service valve and tighten cap.
Compressor is now ready for operation.
REFRIGERANT OIL
Only new, pure, moisture-free refrigerant oil should be used in the air conditioning system. This oil is highly refined and dehydrated to a point
where moisture content is less than 10 parts per million. The oil container must be tightly closed at all times when not in use, or moisture will
be absorbed into the refrigerant oil from the air.
DISCHARGING SYSTEM PRECAUTIONS
If compressor has stem-type service valves, it can be isolated and removed without discharging entire system. Otherwise, discharge system
completely using approved refrigerant recovery/recycling equipment before loosening any fittings.
DISCONNECTING LINES & FITTINGS TEST
After system is discharged, carefully clean area around all fittings to be opened. Always use 2 wrenches when tightening or loosening fittings
to avoid twisting or distorting lines. Cap or plug all openings as soon as lines are removed. Do not remove caps until immediately before
connections are made. This will keep entry of air and moisture to a minimum.
CONNECTING LINES AND FITTINGS
A new gasket or "O" ring should be used in all instances when connecting lines or fittings. Dip "O" ring in new refrigerant oil and ensure it is
not twisted during installation. Always use 2 wrenches to prevent damage to lines and fittings.
PLACING SYSTEM IN OPERATION
After component service or replacement has been completed and all connections have been made, evacuate system thoroughly with a vacuum
pump. Charge system with proper amount of refrigerant and perform a leak test. See REFRIGERANT OIL & R-12 SPECIFICATIONS chart in
this section for system capacities. Be sure to check all fittings that have been opened. After system has been leak tested, make a system
performance check.
ATSUGI ROTARY VANE CLUTCH R & I
Removal
When replacing compressor clutch, be careful not to scratch shaft or bend pulley. When removing center bolt, hold clutch disc with Clutch
Holder (KV99231010). Using Hub Puller (KV998VR001 & KV99231010), remove clutch disc. When removing pulley, remove lock nut with
Hub Socket (KV99235160).
Installation
Wipe oil off clutch surface. Adjust disc pulley clearance to .012-.024" (.3-.6 mm). Tighten center bolt to 80-104 INCH lbs. (9.1-11.8 N.m).
Tighten clutch lock nut to 22-29 ft. lbs. (29-39 N.m). See Fig. 1
. 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:Only com pressors with stem -type service valves can be isolated.
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:Air conditioning system s will not norm ally need addition of refrigerant oil unless definite oil loss has
occurred due to ruptured lines, leaking com pressor seals, com pressor overhaul or com ponent
replacem ent.
Page 1 of 18 MITCHELL 1 ARTICLE - A/C COMPRESSOR SERVICING 1991 GENERAL SERVICING Compressor Service
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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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