2003 FORD MUSTANG low oil pressure

GENERAL PROCEDURES
Refrigerant Oil Adding
CAUTION: During normal A/C operation, oil is circulated through the system with the
refrigerant, and a small amount is retained in each component. If certain components of the
system are removed for new installation, some of the refrigerant oil will go with the component.
To maintain the original total oil charge, it is necessary to compensate for the oil lost by adding
oil to the system with the new part.
1. NOTE: Service A/C compressors are shipped without compressor oil.
Rotate the A/C compressor shaft six to eight revolutions while collecting oil in a clean measuring
device. zIf the amount of oil drained from the old A/C compressor is between 85- 142 ml (3-5
ounces), pour the same amount plus 30 ml (1 ounce) of clean PAG Refrigerant
Compressor Oil (R-134a Systems) F7AZ-19589- DA (Motorcraft YN-12-C) WSH M1C231-
B or equivalent into the new A/C compressor.
z If the amount of oil that was removed from the old A/C compressor is greater than 142 ml
(5 ounces), pour the same amount drained of clean PAG Refrigerant Compressor Oil (R-
134a Systems) or equivalent into the new A/C compressor.
z If the amount of oil that was removed from the old A/C compressor is less than 85 ml (3
ounces), pour 85 ml (3 ounces) of clean PAG Refrigerant Compressor Oil (R- 134a
Systems) or equivalent into the new A/C compressor.
2. For the suction accumulator/drier, drill one 13 mm (0.52 in) hole in the suction accumulator/drier cylinder and drain the oil into a calibrated container.
zAdd a quantity of new oil to match that drained from the old suction accumulator/drier
plus 60 ml (2 ounces) of clean PAG Refrigerant Compressor Oil (R- 134a Systems) or
equivalent.
3. For the A/C evaporator core, add 89 ml (3 ounces) of clean PAG Refrigerant Compressor Oil (R-134a Systems) or equivalent to the suction accumulator/drier inlet tube.
4. For the A/C condenser core, add 30 ml (1 ounce) of clean PAG Refrigerant Compressor Oil (R- 134a Systems) or equivalent to the A/C condenser core or the suction accumulator/drier inlet
tube.
5. Add 60 ml (2 ounces) of clean PAG Refrigerant Compressor Oil (R- 134a Systems) or equivalent
to the suction accumulator/drier inlet tube when carrying out each of the following repairs:
zinstallation of a new A/C evaporator core orifice
z installation of a new A/C compressor pressure relief valve (19D644)
z installation of a new refrigerant line
z repair of an O- ring seal leak
z repair of a charge port leak
6. Installation of new components that do not require discharge of refrigerant and resulting oil loss, such as the A/C cycling switch and the A/C pressure transducer, do not require additional oil.
SECTION 412-
00: Climate Control System - General Information 2003 Mustang Workshop Manual Klj . 1 ba
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A/C Compressor and Clutch Assembly
NOTE:
Internal A/C compressor components are not serviced separately. The FS- 10 A/C compressor
is serviced only as an assembly. The A/C clutch pulley, A/C clutch field coil (19D798) and the shaft
seal are serviceable.
The FS- 10 A/C compressor has the following characteristics:
z A ten- cylinder swashplate design utilizing the tangential design mount. Item Part Number Description
1 19E561 A/C cycling switch
2 19D701 A/C charge port valve (low side)
3 19D594 Refrigerant containment switch (3.8L vehicles)
3 19D594 Dual-
function pressure switch (4.6L vehicles) 4 19D734 A/C manifold and tube
5 19D644 A/C compressor pressure relief valve
6 19703 A/C compressor
7 19D701 A/C charge port valve (high side)
8 19712 A/C condenser core
9 19835 Condenser to evaporator tube
10 19C836 Suction accumulator
11 — A/C evaporator core (part of 19850 assembly) Klj . 2 ba
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z
A one- piece lip- type seal (installed from the front of the A/C compressor) is used to seal it at the
shaft opening in the assembly.
z Five double- acting pistons operate within the cylinder assembly. The pistons are actuated by a
swashplate that converts the rotating action of the shaft to a reciprocating force.
z Reed- type discharge valves are located between the cylinder assembly and the head at each
end of the A/C compressor.
z The A/C compressor uses PAG oil, or equivalent. This oil contains special additives required for
the A/C compressor.
z The A/C compressor oil from vehicles equipped with an FS- 10 A/C compressor may have some
dark colored streaking while maintaining a normal oil viscosity. This is normal for the A/C
compressor and is caused by break- in wear of the piston rings.
The magnetic A/C clutch has the following characteristics: zIt drives the compressor shaft.
z When the battery positive voltage (B+) is applied to the A/C clutch field coil, the clutch plate and
hub assembly is drawn toward the A/C clutch pulley.
z The magnetic force locks the clutch plate and hub assembly and the A/C clutch pulley together
as one unit, causing the compressor shaft to rotate.
z When (B+) is removed from the A/C clutch field coil, springs in the clutch plate and hub
assembly move the clutch plate away from the A/C clutch pulley. A/C Compressor Pressure Relief Valve Item Part Number Description
1 19D798 A/C clutch field coil
2 19D784 A/C clutch pulley
3 N805338-S2 Pulley snap ring
4 19D648 A/C clutch hub spacer
5 19D786 Disk and hub assembly
6 N805332-S2 A/C clutch bolt Klj . 3 ba
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A/C Evaporator Core
NOTE:
The evaporator core is not separately serviceable, it is serviced only with the evaporator core
housing assembly.
NOTE: Installation of a new suction accumulator is not required when repairing the air conditioning
system except when there is physical evidence of contamination from a failed A/C compressor or
damage to the suction accumulator.
The A/C evaporator core is the plate/fin type with a unique refrigerant flow path.
zA mixture of refrigerant and oil enters the bottom of the A/C evaporator core through the A/C
evaporator core inlet tube and moves out of the A/C evaporator core through the A/C
evaporator core outlet tube.
z This flow pattern accelerates the flow of refrigerant and oil through the A/C evaporator core.
Evaporator Core Orifice
NOTE: The evaporator core orifice is an integral part of the condenser to evaporator line and should
be installed as an assembly with the line.
NOTE: A new evaporator core orifice should be installed whenever a new A/C compressor is installed.
The evaporator core orifice has the following characteristics:
zIt is located in the A/C condenser to evaporator line.
z It has filter screens located on the inlet and outlet ends of the tube body.
z The inlet filter screen acts as a strainer for the liquid refrigerant flowing through the evaporator
core orifice.
z O-ring seals on the evaporator core orifice prevent the high- pressure liquid refrigerant from
bypassing the evaporator core orifice. Klj . 5 ba
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z
Adjustment or repair cannot be made to the evaporator core orifice assembly. A new evaporator
core orifice must be installed as a unit.
Suction Accumulator
NOTE: Installation of a new suction accumulator is not required when repairing the air conditioning
system except when there is physical evidence of contamination from a failed A/C compressor or
damage to the suction accumulator.
In addition to the preceding condition, a new suction accumulator should be installed if one of the
following conditions exist:
zThe suction accumulator is perforated.
z The refrigerant system has been opened to the atmosphere for a period of time longer than
required to make a minor repair.
z There is evidence of moisture in the system such as internal corrosion of metal refrigerant lines
or the refrigerant oil is thick and dark. Item Part Number Description
1 19E561 A/C cycling switch
2 — O-
ring seal (part of 19C836) 3 19D701 Low pressure service gauge port valve
4 — Inlet from A/C evaporator core (part of 19C836)
5 — Outlet to A/C compressor (part of 19C836)
6 — Anti-
siphon hole (part of 19C836) 7 — Desiccant bag (part of 19C836)
8 — Oil return orifice filter (part of 19C836)
9 — Vapor return tube (part of 19C836)
10 — Suction accumulator dome (part of 19C836) Klj . 6 ba
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The suction accumulator (19C836) is mounted to the A/C accumulator bracket (19D606) to the right of
the vehicle centerline. The inlet tube of the suction accumulator attaches directly to the A/C evaporator
core outlet tube and the outlet tube attaches to the A/C manifold and tube.
After entering the inlet of the suction accumulator, the heavier oil-
laden refrigerant contacts an
internally mounted dome (which serves as an umbrella) and drips down onto the bottom of the
canister.
zA small diameter oil bleed hole, in the bottom of the vapor return tube, allows the accumulated
heavier liquid refrigerant and oil mixture to reenter the compressor suction line at a controlled
rate.
z As the heavier mixture passes through the small diameter liquid bleed hole, it has a second
chance to vaporize and recirculate through the A/C compressor without causing compressor
damage due to slugging.
z A fine mesh screened filter fits tightly around the bottom of the vapor return tube to filter out
refrigerant system contaminant particles.
z A desiccant bag is mounted inside the canister to absorb any moisture which may be in the
refrigerant system.
z A fitting located on the top of the suction accumulator is used to attach the A/C cycling switch. A
long- travel Schrader- type valve stem core is installed in the fitting so that the A/C cycling switch
can be removed without discharging the A/C system.
A/C Cycling Switch
The A/C cycling switch is mounted on a Schrader- type valve fitting on the top of the suction
accumulator.
zA valve depressor, located inside the threaded end of the A/C cycling switch, presses in on the
Schrader valve stem.
z This allows the suction pressure inside the suction accumulator to control the operation of the
A/C cycling switch.
z The electrical switch contacts open when the suction pressure drops. The contacts close when
the suction pressure rises. For specifications regarding operating pressure(s), refer to Section 412 - 00 .
z The A/C cycling switch will control the A/C evaporator core pressure at a point where the
plate/fin surface temperature will be maintained slightly above freezing.
z This prevents icing of the A/C evaporator core and blockage of air flow.
z It is not necessary to discharge the refrigerant system to remove the A/C cycling switch.
Dual- Function Pressure Switch (4.6L)
The dual- function pressure switch is used to interrupt A/C compressor operation in the event of high Klj . 7 ba
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REMOVAL AND INSTALLATION
Air Conditioning (A/C) Pressure Relief Valve —
3.8L
Removal and Installation 1. Recover the refrigerant. For additional information, refer to Section 412 - 00 .
2. Unlatch the breather.
3. Disconnect the mass air flow (MAF) sensor electrical connector.
4. Remove the air cleaner outlet tube. 1. Loosen the clamp.
2. Disconnect the crankcase ventilation tube.
3. Remove the air cleaner outlet tube.
SECTION 412-
03: Air Conditioning 2003 Mustang Workshop Manual Material
Item Specification
PAG Refrigerant Compressor
Oil (R-
134a Systems)
F7AZ- 19589- DA (Motorcraft YN-
12- C) WSH-
M1C231-
B Klj . 1 ba
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DESCRIPTION AND OPERATION
Instrument Cluster
The instrument cluster (10849) consists of the following components:
Instrument Cluster—
Base 3.8L Engine
SECTION 413-
01: Instrument Cluster 2003 Mustang Workshop Manual Item Part
Number Description
1 — Fuel gauge
2 — Engine coolant temperature gauge
3 — Speedometer
4 — Turn signal/hazard indicator
5 — High beam indicator
6 — Tachometer
7 — Odometer
8 — Trip odometer reset button
9 — Voltmeter gauge
10 — Oil pressure gauge
11 — CHECK FUEL CAP indicator
12 — BRAKE warning indicator
13 — ABS warning indicator
14 — Traction control indicator
15 — Overdrive off (O/D OFF) indicator (automatic Klj . 1 ba
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