2003 FORD MUSTANG oil temperature

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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COOL (blue) to WARM (red) causes a corresponding movement on the air temperature control
door and determines the temperature that the system will maintain.
z The A/C heater function selector switch combines a vacuum selector valve for direct control of
the vacuum control motors and electrical input to the instrument control module.
Control System Outputs
Blower Motor Switch Resistor
The heater blower motor switch resistor has the following features:
zThe assembly is located on the passenger side of the plenum assembly behind the glove
compartment (06010).
z Three resistance elements are mounted on the resistor board to provide four A/C blower motor
speeds.
z Depending on the heater blower motor switch position, series resistance is added or bypassed
in the A/C blower motor circuit to decrease or increase A/C blower motor speed.
z An overheating protective device (thermal limiter) will open the resistor coil circuit when the
temperature reaches 105°- 110°C (221°-230°F), interrupting the blower motor operation in all
speeds except HI.
z The thermal limiter cannot be reset and is not serviceable.
Control Actuators
Temperature Control Cable
The temperature control cable (19988) has the following features:
zThe cable assembly has a constant tension (pull- pull) dual cable design.
z The pull- pull design allows for constant smooth communication between the temperature control
knob and the air temperature blend door.
z The control cable can only be installed as an assembly.
Vacuum Control Motors
The vacuum control motors (18A318) control the position of the doors directing the air flow to the
different outlets. There are two types of vacuum control motors used in this system:
zSingle- diaphragm for air inlet and windshield defroster door operations.
z Double- diaphragm for air damper door operations.
Single- diaphragm motors have two positions:
z Shaft extended with no vacuum applied.
z Shaft retracted with vacuum applied.
Double- diaphragm motors have three positions:
z Shaft extended with no vacuum applied to either port.
z Shaft halfway retracted with vacuum applied to only one port. Klj . 3 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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Instrument Cluster—
Base 4.6L Engine transmission)
16 — LOW FUEL level indicator
17 — SERVICE ENGINE SOON indicator
18 — THEFT indicator
19 — AIR BAG warning indicator
20 — Charging system indicator
21 — Safety belt warning indicator
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 Klj . 2 ba
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Instrument Cluster—
Cobra 14 — Traction control indicator
15 — Overdrive off (O/D OFF) indicator (automatic
transmission)
16 — LOW FUEL level indicator
17 — SERVICE ENGINE SOON indicator
18 — THEFT indicator
19 — AIR BAG warning indicator
20 — Charging system indicator
21 — Safety belt warning indicator
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 — Boost gauge
10 — Oil pressure gauge
11 — CHECK FUEL CAP indicator
12 — BRAKE warning indicator Klj . 3 ba
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Odometer
Display Description
GAGE Activates gauge sweep of all gauges, then displays present gauge values. Also
carries out the checksum tests on ROM and EE. All segments
illuminated Illuminates all odometer segments.
bulb Illuminates all micro-controlled indicators and LEDs. Install a new indicator or LED as
necessary. r Returns to normal operation of all micro-
controlled indicators and LEDs and displays
hexadecimal value for ROM level (used when requesting assistance from the hotline). EE Displays hexadecimal value for EE level (used when requesting assistance from the
hotline). dt Displays hexadecimal coding of final manufacturing test date (used when requesting
assistance from the hotline). dtc Displays continuous DTCs in hexadecimal format. Pressing the SELECT/RESET
button will display any DTCs stored before proceeding to the next step. enG Displays the English speed in mph. Speedometer will indicate present speed within
tolerances. Display will show 0 if input is not received, if input received is invalid for one second or more, or if speed is 0. m Displays the metric speed data (km/h). Speedometer will indicate present speed
within tolerances. Display will show 0 if input is not received, if input received is invalid for one second or more, or if speed is 0. tAc Displays the tachometer data received from the PCM via the SCP network within
tolerances. Tachometer will indicate present rpm. Display will show 0 if input is not received, if input received is invalid for one second or more, or if engine rpm is 0. FUEL Displays the code (0-255) for the fuel sender input to the instrument cluster. The fuel
gauge will display a filtered fuel level value. This filter will keep the pointer from moving suddenly or erratically.
z255 = open send +/- 0
z 232 = full stop +/- 0
z 215 = full mark +/- 10
z 178 = 3/4 mark +/- 8
z 138 = 1/2 mark +/- 7
z 93 = 1/4 mark +/- 5
z 41 = E mark +/- 4
z 54=LOW FUEL (0- 59)
z 0-18=short (0- 20 max) OIL Displays the code (0-
250) for the oil pressure switch input to the instrument cluster.
Oil pressure gauge will indicate present oil pressure. Normal oil pressure (greater
than 6 psi) will display a value between 000 and 176. A low oil pressure or an
inoperative engine oil pressure switch (less than 6 psi) will display a value greater
than 176. dEGC Display of engine temperature in degrees C input from cylinder head temperature
sensor.
z 49 C = "C" mark
z 60 C = normal band start
z 120 C = normal band end
z -40 C = no SCP message for 5 seconds bAtt Displays the code (0-255) for the battery voltage input to the instrument cluster.
Battery voltage gauge will indicate present battery voltage. Klj . 6 ba
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(20A).
z Battery junction
box (BJB) fuse
12 (40A).
z Circuitry.
z GEM.
z No communication with
the instrument cluster z
Central junction
box (CJB) fuse
(s):
„11
(15A).
„ 21 (5A).
„ 34
(20A).
z Circuitry.
z Standard
corporate
protocol (SCP)
network.
z Instrument
cluster. z
Go To Pinpoint Test A .
z Incorrect fuel gauge
indication z
Circuitry.
z Fuel pump
module.
z Instrument
cluster. z
Go To Pinpoint Test B .
z Incorrect oil pressure
gauge indication z
Circuitry.
z Engine oil
pressure
switch.
z Instrument
cluster. z
Go To Pinpoint Test C .
z Incorrect temperature
gauge indication z
Circuitry.
z Engine coolant
temperature
sensor.
z Powertrain
control module
(PCM).
z Instrument
cluster. z
Go To Pinpoint Test D .
z Incorrect voltage gauge
indication— except
Cobra z
Circuitry.
z Generator.
z Standard
corporate
protocol (SCP)
network.
z Instrument
cluster. z
Go To Pinpoint Test E .
z Incorrect tachometer
indication z
Standard
corporate
protocol (SCP)
network.
z Powertrain
control module
(PCM).
z Instrument
cluster. z
Go To Pinpoint Test F .
z Incorrect boost gauge zPressure line. zGo To Pinpoint Test G . Klj . 10 ba
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DESCRIPTION AND OPERATION
Charging System
The charging system is a negative ground system consisting of the following:
zgenerator
z internal voltage regulator
z charging system warning indicator
z storage battery
z necessary wiring and cables
The generator is belt- driven by the engine accessory drive system.
With the ignition key in the run position, voltage is applied through the warning indicator I circuit to the
voltage regulator. This turns the regulator on, allowing current to flow from battery sense A circuit to
the generator field coil. When the engine is started, the generator begins to generate alternating
current (AC) which is converted to direct current (DC) internally. This current is then supplied to the
vehicle's electrical system through the output terminal (B+) of the generator.
Once the generator begins generating current, a voltage signal is taken from the generator stator and
fed back to the internal regulator. This voltage feedback signal (typically half the battery voltage) is
used to turn off the warning indicator.
With the system functioning normally, the generator output current is determined by the voltage of the
A circuit. This A circuit voltage (battery sense circuit) is compared to a set voltage internal to the
regulator, and the regulator controls the generator field current to maintain the correct generator
output.
The set voltage will vary with temperature and is typically higher in cold temperatures than in warm
temperatures. This allows for better battery recharge in the winter and reduces the chance of
overcharging in the summer.
The battery is a 12 volt direct current source connected in a negative ground system. The battery case
is sealed and includes two vent holes to release gases. The battery has three major functions:
zengine cranking power source
z voltage stabilizer for the electrical system
z temporary power when electrical loads exceed the generator output current
Circuit Description
Battery Output Terminal (B+)
The generator output is supplied through the battery positive output (B+) terminal on the back of the
generator to the battery and electrical system.
I Circuit 904 (LG/RD)
The I (ignition) circuit is used to turn on the voltage regulator. This circuit is powered up with the
ignition key in the run position. This circuit is also used to turn the charging system warning indicator
on if there is a fault in the charging system operation. SECTION 414-
00: Charging System — General Information 2003 Mustang Workshop Manual Klj . 1 ba
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