Charging System - General Information Lincoln Town Car III рестайлинг

GENERAL SPECIFICATIONS

GENERAL SPECIFICATIONS

The charging system consists of the following

1. Generator
2. Charging system warning indicator
3. Necessary wiring and cables

The charging system is a negative ground system. The generator (including an internal voltage regulator) is belt-driven by the engine accessory drive system. When the engine is started, the generator begins to generate AC, which is internally converted to DC. This current is then supplied to the vehicle electrical system through the output (B+) terminal of the generator.

Battery

The battery is a 12-volt DC source connected in a negative ground system. The battery case is sealed with 2 vent holes to release gases. The battery has 3 major functions

1. Engine cranking power source
2. Voltage stabilizer for the electrical system
3. Temporary power source when electrical loads exceed the generator output current.

Special Tools Illustration Tool Name Tool Number 73III Automotive Meter 105-R0057 or equivalent SABRE Premium Battery and Electrical System Tester 010-00736 or equivalent Vehicle Communication Module (VCM) and Integrated Diagnostic System (IDS) software with appropriate hardware, or equivalent scan tool Flex Probe Kit 105-R025B

Scheme 2

Scheme 3

Principles of Operation

The powertrain control module (PCM)-controlled charging system determines the optimal voltage setpoint for the charging system and communicates this information to the voltage regulator. This system is unique in that it has 2 unidirectional communication lines between the PCM and the generator/regulator. Both of these communication lines are pulse-width modulated (PWM). The generator communication (GEN COM) line communicates the desired setpoint from the PCM to the voltage regulator. The generator monitor (GEN MON) line communicates the generator load and error conditions to the PCM. The third pin on the voltage regulator is a dedicated battery voltage sense line.

The charging system voltage is controlled by the PCM. The generator charges the battery, and at the same time supplies power for all of the electrical loads that are required. The battery is more effectively charged with a higher voltage when the battery is cold and a lower voltage when the battery is warm. The PCM is able to adjust the charging voltage according to the battery temperature by using a signal from the intake air temperature (IAT) sensor. This means the voltage setpoint is calculated by the PCM and communicated to the regulator by a communication link.

The PCM simultaneously controls and monitors the output of the generator. When the current consumption is high or the battery is discharged, the system is able to increase the idle speed.

To minimize the engine drag when starting the engine, the PCM controls the generator. The generator does not produce any output until the engine has started. The PCM then progressively increases the output of the generator.

The PCM controls the operation of the charging system warning indicator in the instrument cluster. The PCM is responsible for turning the charging system warning indicator off after the engine is started and illuminating it under fault conditions (when the generator is not generating the correct amount of current with the engine running). The charging system warning indicator is also illuminated by the PCM at key ON engine OFF, and a stall condition.

This is a System 4 charging system, which uses the GEN MON and GEN COM lines to control and monitor the charging system through the PCM. System 4 charging systems are virtually identical in design and therefore, share the same diagnostics. The circuit numbers and colors may be different, but the functions are the same. System 4 charging systems may use any type of generator, as the generator type usually depends on the engine packaging and/or output requirements versus cost.

Positive Battery Output (B+) Terminal Circuit 2037 (RD)

Generator output voltage is supplied through the positive battery (B+) output terminal on the rear of the generator to the battery and the electrical system.

Circuit 35 (OG/LB)

This is the battery voltage sense circuit and is used to sense battery voltage.

Circuit 1816 (YE/LB)

This is the GEN COM circuit. The PCM determines the optimal voltage setpoint for the charging system and communicates the information to the voltage regulator via the GEN COM circuit.

Circuit 1817 (YE)

The GEN MON circuit communicates the generator load and error conditions to the PCM.

Inspection and Verification

Note. While carrying out any pinpoint test, disregard the diagnostic trouble codes (DTCs) set while following a specific pinpoint test. After the completion of any test, be sure to clear all DTCs in the PCM.

Note. All voltage measurements are referenced to the negative (-) battery post unless otherwise specified.

1. Verify the customer concern.
2. Visually inspect for obvious signs of mechanical or electrical damage. VISUAL INSPECTION CHART Mechanical Electrical Battery Generator drive belt Generator pulley Battery junction box (BJB) fuse 6 (15A) Fusible link A Circuitry Cables Generator Powertrain control module (PCM) Charging system warning indicator
3. If an obvious cause for an observed or reported concern is found, correct the cause (if possible) before proceeding to the next step.
4. Verify the battery condition. Refer to «BATTERY, MOUNTING AND CABLES»(/lincoln/town-car/iii-2003-2011/remont/body-electrical/#battery-mounting-and-cables) article.
5. Check the operation of the charging system warning indicator (instrument cluster). Normal operation is as follows: With the key OFF, the charging system warning indicator should be off. With the key ON and the engine off, the charging system warning indicator should be on. With the engine running, the charging system warning indicator should be off.
6. Turn off the headlamps and the A/C system (if equipped). Turn the climate control blower to LOW/OFF. Check the battery voltage before and after starting the engine to determine if the battery voltage increases.
7. If the cause is not visually evident, connect the scan tool to the data link connector (DLC).
8. If the scan tool does not communicate with the VCM: check the VCM connection to the vehicle. check the scan tool connection to the VCM. refer to «MODULE COMMUNICATIONS NETWORK»(/lincoln/town-car/iii-2003-2011/remont/communication-devices/#module-communications-network-system) article, No power to the scan tool, to diagnose no communication with the scan tool.
9. If the scan tool does not communicate with the vehicle: verify the ignition key is in the ON position. refer to «MODULE COMMUNICATIONS NETWORK»(/lincoln/town-car/iii-2003-2011/remont/communication-devices/#module-communications-network-system) article to diagnose no response from the powertrain control module (PCM).
10. Carry out the network test. If the scan tool responds with no communication for one or more modules, refer to «MODULE COMMUNICATIONS NETWORK»(/lincoln/town-car/iii-2003-2011/remont/communication-devices/#module-communications-network-system) article. If the network test passes, retrieve and record continuous memory diagnostic trouble codes (DTCs).
11. Clear the continuous DTCs and carry out the self-test diagnostics for the PCM and the instrument cluster.
12. If the DTCs retrieved are related to the concern, go to «POWERTRAIN CONTROL MODULE (PCM) DIAGNOSTIC TROUBLE CODE (DTC) INDEX»(/lincoln/town-car/iii-2003-2011/remont/charging-system/#charging-system-general-information) or «INSTRUMENT CLUSTER DIAGNOSTIC TROUBLE CODE (DTC) INDEX»(/lincoln/town-car/iii-2003-2011/remont/charging-system/#charging-system-general-information) . For all other DTCs, refer to «MULTIFUNCTION ELECTRONIC MODULES»(/lincoln/town-car/iii-2003-2011/remont/communication-devices/#multifunction-electronic-modules-system) article.
13. If no DTCs related to the concern are retrieved, go to «Symptom Chart»(/lincoln/town-car/iii-2003-2011/remont/charging-system/#charging-system-general-information) .

Note. DTC P0622 can be set by the loss of the communication lines between the generator and the PCM. The charging system warning indicator then illuminates until the engine is operated at greater than 4,500 RPM (approximately wide open throttle [WOT]) for a minimum of 3 seconds. At this time, the generator self-excites. The charging system warning indicator remains illuminated, and the generator operates in a default mode (approximately 13.5 volts) until the engine is turned off.

POWERTRAIN CONTROL MODULE (PCM) DIAGNOSTIC TROUBLE CODE (DTC) INDEX

INSTRUMENT CLUSTER DIAGNOSTIC TROUBLE CODE (DTC) INDEX

Symptom Chart

Symptom Chart

Pinpoint Test A: The Battery is Discharged or Battery Voltage is Low

Refer to SYSTEM WIRING DIAGRAMS article, Charging System for schematic and connector information.

Normal Operation

The generator output is supplied through the positive battery output (B+) circuit 2037 (RD) terminal on the rear of the generator to the battery and electrical system. During normal operation, the charging system warning indicator is off with the key in the ON position and the engine running. The charging system warning indicator is on with the key in the ON position and the engine off.

Possible Causes

1. Circuit 2037 (RD) high resistance
2. Engine, generator and battery grounds
3. High key-off current drain(s)
4. Battery
5. Generator

Scheme 4

Scheme 5

1. A1 CHECK THE BATTERY CONDITION Carry out the Battery - Condition Test to determine if the battery can hold a charge and is OK for use. Refer to «BATTERY, MOUNTING AND CABLES»(/lincoln/town-car/iii-2003-2011/remont/body-electrical/#battery-mounting-and-cables) article. Does the battery pass the condition test? YES : Go to A2 . NO : INSTALL a new battery. REFER to «BATTERY, MOUNTING AND CABLES»(/lincoln/town-car/iii-2003-2011/remont/body-electrical/#battery-mounting-and-cables) article. TEST the system for normal operation.
2. A2 CHECK THE GENERATOR OUTPUT Carry out the Generator On-Vehicle Load Test and No Load Test. Refer to «Component Tests»(/lincoln/town-car/iii-2003-2011/remont/charging-system/#charging-system-general-information) . Does the generator pass the component tests? YES : Go to A3 . NO : INSTALL a new generator. REFER to «GENERATOR AND REGULATOR»(/lincoln/town-car/iii-2003-2011/remont/charging-system/#charging-system-generator-regulator) article. TEST the system for normal operation.
3. A3 CHECK FOR CURRENT DRAINS Carry out the Battery - Drain Testing. Refer to «Component Tests»(/lincoln/town-car/iii-2003-2011/remont/charging-system/#charging-system-general-information) . Are any circuits causing excessive current drains? YES : REPAIR as necessary. TEST the system for normal operation. NO : Go to A4 .
4. A4 CHECK THE VEHICLE GROUNDS Key in START position. With the engine running, measure the voltage drop between the generator housing and the negative battery terminal. Is the voltage drop less than 0.1 volt? YES : Go to A5 . NO : CHECK the engine ground, generator ground and the battery ground for corrosion. TEST the system for normal operation.
5. A5 CHECK THE VOLTAGE DROP IN THE B+ CIRCUIT 2037 (RD) With the engine running, measure the voltage drop between the generator B+ C102b, circuit 2037 (RD) and the positive battery terminal. Is the voltage drop less than 0.1 volt? YES : CHECK if the customer left any component(s) on or if there is an intermittent excessive battery draw. TEST the system for normal operation. NO : CHECK for any corrosion in the generator B+ circuit 2037 (RD), positive battery cable and/or connections. REPAIR or REPLACE the battery cables. REFER to «BATTERY, MOUNTING AND CABLES»(/lincoln/town-car/iii-2003-2011/remont/body-electrical/#battery-mounting-and-cables) article. TEST the system for normal operation.

Pinpoint Test B: The Charging System Warning Indicator is ON With the Engine Running (The Charging System Voltage Does Not Increase)

Refer to SYSTEM WIRING DIAGRAMS article, Charging System for schematic and connector information.

With the engine running, the charging system warning indicator is off. The sense circuit 35 (OG/LB) to the generator field coil is 13-15 volts. The S (stator) circuit (internal to the generator) is used to feed back a voltage signal from the generator to the voltage regulator. This voltage is used by the powertrain control module (PCM) to turn off the charging system warning indicator. The positive battery output (B+) circuit 2037 (RD) is the generator output supplied to the battery and the electrical system.

Possible Causes

1. Circuit 2037 (RD) open or high resistance
2. Circuit 1817 (YE) open or short to ground
3. Circuit 1816 (YE/LB) open or short to ground
4. Generator
5. PCM

Scheme 6

Scheme 7

Scheme 8

Scheme 9

1. B1 CHECK THE DIAGNOSTIC TROUBLE CODES (DTCS) IN THE PCM Key in OFF position. Connect the diagnostic tool. Key in ON position. Enter the following diagnostic mode on the diagnostic tool: Retrieve PCM DTCs Check for recorded PCM DTCs from the continuous and on-demand self tests. Are any PCM DTCs recorded? YES : REFER to the «Introduction - Gasoline Engines»(/lincoln/town-car/iii-2003-2011/remont/testing-diagnostics/#engine-controls-introduction-except-diesel-hybrid) article. If referred here by the «Introduction - Gasoline Engines»(/lincoln/town-car/iii-2003-2011/remont/testing-diagnostics/#engine-controls-introduction-except-diesel-hybrid) article, go to B2 . NO : Go to B2 .
2. B2 CHECK THE GENERATOR B+ CIRCUIT 2037 (RD) FOR VOLTAGE Key in OFF position. Measure the voltage between generator C102b, circuit 2037 (RD) and ground. Is the voltage equal to battery voltage? YES : Go to B3 . NO : REPAIR the circuit. TEST the system for normal operation.
3. B3 CHECK THE GENERATOR INTEGRITY Disconnect: Generator C102a Key in ON position, engine OFF. Measure and record the battery voltage. Key in START position. NOTE: If the generator communication lines are disconnected (DTC P0622 may set), the generator self-excites if it is operated at greater than 4,500 RPM (approximately wide open throttle [WOT]) for a minimum of 3 seconds. It then operates in a default mode of 13.5 volts until the engine is turned off. With the engine running (after the brief WOT is carried out), measure the battery voltage. Does the battery voltage increase a minimum of 0.5 volt from the key ON, engine off measurement to the key ON, engine running measurement (after the brief WOT or snap acceleration is carried out)? YES : Go to B4 . NO : INSTALL a new generator. REFER to «GENERATOR AND REGULATOR»(/lincoln/town-car/iii-2003-2011/remont/charging-system/#charging-system-generator-regulator) article. TEST the system for normal operation.
4. B4 CHECK CIRCUIT 1816 (YE/LB) FOR AN OPEN OR A SHORT TO GROUND Key in OFF position. Disconnect: PCM C175t Measure the resistance between generator C102a-2, circuit 1816 (YE/LB), harness side and PCM C175t-19, circuit 1816 (YE/LB), harness side; and between generator C102a-2, circuit 1816 (YE/LB), harness side and ground. Is the resistance less than 5 ohms between the generator and the PCM, and greater than 10,000 ohms between the generator and ground? YES : Go to B5 . NO : REPAIR the circuit. TEST the system for normal operation.
5. B5 CHECK CIRCUIT 1817 (YE) FOR AN OPEN OR A SHORT TO GROUND Measure the resistance between generator C102a-1, circuit 1817 (YE), harness side and PCM C175t-38, circuit 1817 (YE), harness side; and between generator C102a-1, circuit 1817 (YE), harness side and ground Is the resistance less than 5 ohms between the generator and the PCM, and greater than 10,000 ohms between the generator and ground? YES : Go to B6 . NO : REPAIR the circuit. TEST the system for normal operation.
6. B6 CHECK FOR CORRECT PCM OPERATION Disconnect all of the PCM connectors. Check for: corrosion. pushed-out pins. Connect all of the PCM connectors and make sure they seat correctly. Operate the system and verify the concern is still present. Is the concern still present? YES : INSTALL a new PCM. REFER to «ELECTRONIC ENGINE CONTROLS»(/lincoln/town-car/iii-2003-2011/remont/removal-installation/#electronic-engine-controls) article. REPEAT the self-test. TEST the system for normal operation. NO : The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.

Pinpoint Test C: The Charging System Overcharges (Battery Voltage Is Greater Than 15.5 Volts)

Refer to SYSTEM WIRING DIAGRAMS article, Charging System for schematic and connector information.

The generator output is determined by the voltage of the circuit 35 (OG/LB). The circuit voltage 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 varies with temperature and is typically higher in cold temperatures and lower in warm temperatures.

Possible Causes

1. Circuit 35 (OG/LB)
2. Fuse
3. Generator
4. Powertrain control module (PCM)

Scheme 10

1. C1 CHECK THE DIAGNOSTIC TROUBLE CODES (DTCS) IN THE PCM Key in OFF position. Connect the diagnostic tool. Key in ON position. Enter the following diagnostic mode on the diagnostic tool: Retrieve PCM DTCs Check for recorded PCM DTCs from the continuous and on-demand self tests. Are any PCM DTCs recorded? YES : REFER to the «Introduction - Gasoline Engines»(/lincoln/town-car/iii-2003-2011/remont/testing-diagnostics/#engine-controls-introduction-except-diesel-hybrid) article. If referred here by the «Introduction - Gasoline Engines»(/lincoln/town-car/iii-2003-2011/remont/testing-diagnostics/#engine-controls-introduction-except-diesel-hybrid) article, go to C2 . NO : Go to C2 .
2. C2 CHECK THE BATTERY VOLTAGE Key in OFF position. Disconnect the diagnostic tool. Key in START position. With the engine running and all of the accessories turned off, measure the voltage at the battery while varying the engine RPM. Is the voltage greater than 15.5 volts? YES : Go to C3 . NO : Go to C4 .
3. C3 CHECK FOR A VOLTAGE DROP IN CIRCUIT 35 (OG/LB) Key in OFF position. Disconnect: Generator C102a Measure the voltage between generator C102a-3, circuit 35 (OG/LB), harness side and ground. Is the voltage within 0.5 volt from battery voltage? YES : CONNECT the generator C102a. Go to C4 . NO : VERIFY the battery junction box (BJB) fuse 6 (15A) is OK. If OK, REPAIR the circuit for high resistance. TEST the system for normal operation.
4. C4 CHECK THE GENERATOR PIDS Connect the diagnostic tool. Key in START position. Enter the following diagnostic mode on the diagnostic tool: Monitor PCM PIDs With the engine running, monitor the generator output fault PID in the PCM. Does the PID read YES? YES : Go to C5 . NO : Go to C6 .
5. C5 CHECK THE GENERATOR INTEGRITY Key in OFF position. Disconnect: Generator C102a Key in ON position, engine OFF. Measure and record the battery voltage. Key in START position. NOTE: If the generator communication lines are disconnected (DTC P0622 may be set), the generator self-excites if it is operated at greater than 4,500 RPM (approximately wide open throttle [WOT]) for a minimum of 3 seconds. It then operates in a default mode at 13.5 volts until the engine is turned off. With the engine running (after the brief WOT is carried out), measure the battery voltage. Does the battery voltage increase a minimum of 0.5 volt from the key ON, engine off measurement to the key ON, engine running measurement (after the brief WOT or snap acceleration is carried out)? YES : Go to C6 . NO : INSTALL a new generator. REFER to «GENERATOR AND REGULATOR»(/lincoln/town-car/iii-2003-2011/remont/charging-system/#charging-system-generator-regulator) article. TEST the system for normal operation.
6. C6 CHECK FOR CORRECT PCM OPERATION Key in OFF position. Disconnect all of the PCM connectors. Check for: corrosion. pushed-out pins. Connect all of the PCM connectors and make sure they seat correctly. Operate the system and verify the concern is still present. Is the concern still present? YES : INSTALL a new PCM. REFER to «ELECTRONIC ENGINE CONTROLS»(/lincoln/town-car/iii-2003-2011/remont/removal-installation/#electronic-engine-controls) article. REPEAT the self-test. TEST the system for normal operation. NO : The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.

Pinpoint Test D: The Charging System Warning Indicator is ON with the Engine Running and the Battery Increases Voltage

Refer to SYSTEM WIRING DIAGRAMS article, Charging System for schematic and connector information.

With the engine running, the charging system warning indicator is off. The sense circuit 35 (OG/LB) to the generator field coil is 13-15 volts. The S (stator) circuit (internal to the generator) is used to feed back a voltage signal from the generator to the voltage regulator. This voltage is monitored by the powertrain control module (PCM) to turn off the charging system warning indicator. The positive battery output (B+) circuit 2037 (RD) is the generator output supplied to the battery and the electrical system.

Possible Causes

1. Generator
2. Instrument cluster
3. PCM

1. D1 CHECK THE DIAGNOSTIC TROUBLE CODES (DTCs) IN THE PCM Key in OFF position. Connect the diagnostic tool. Key in ON position. Enter the following diagnostic mode on the diagnostic tool: Retrieve PCM DTCs Check for recorded PCM DTCs from the continuous and on-demand self tests. Are any PCM DTCs recorded? YES : REFER to the «Introduction - Gasoline Engines»(/lincoln/town-car/iii-2003-2011/remont/testing-diagnostics/#engine-controls-introduction-except-diesel-hybrid) article. If referred here by the «Introduction - Gasoline Engines»(/lincoln/town-car/iii-2003-2011/remont/testing-diagnostics/#engine-controls-introduction-except-diesel-hybrid) article, go to D2 . NO : Go to D2 .
2. D2 CHECK THE SYSTEM FOR OVERCHARGING Key in START position. With the engine running and all of the accessories off, measure the voltage at the battery terminals while varying the engine RPM. Is the voltage greater than 15.5 volts? YES : Go to «Pinpoint Test C»(/lincoln/town-car/iii-2003-2011/remont/charging-system/#charging-system-general-information__pinpoint-test-c-the-charging-system) . NO : Go to D3 .
3. D3 CHECK THE PCM PIDS Enter the following diagnostic mode on the diagnostic tool: Monitor PCM PIDs With the engine running, monitor the generator output fault PID in the PCM. Does the PID read YES? YES : Go to D4 . NO : REFER to «INSTRUMENT CLUSTER»(/lincoln/town-car/iii-2003-2011/remont/gauges-instrument-panels/#instrument-cluster-system) article to diagnose the charging system warning indicator.
4. D4 CHECK THE GENERATOR OUTPUT Verify the generator output. Refer to «Component Tests»(/lincoln/town-car/iii-2003-2011/remont/charging-system/#charging-system-general-information) , Generator On-Vehicle Tests. Does the generator pass the component tests? YES : Go to D5 . NO : INSTALL a new generator. REFER to «GENERATOR AND REGULATOR»(/lincoln/town-car/iii-2003-2011/remont/charging-system/#charging-system-generator-regulator) article. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.
5. D5 CHECK FOR CORRECT PCM OPERATION Key in OFF position. Disconnect all of the PCM connectors. Check for: corrosion. pushed-out pins. Connect all of the PCM connectors and make sure they seat correctly. Operate the system and verify the concern is still present. Is the concern still present? YES : INSTALL a new PCM. REFER to «ELECTRONIC ENGINE CONTROLS»(/lincoln/town-car/iii-2003-2011/remont/removal-installation/#electronic-engine-controls) article. REPEAT the self-test. TEST the system for normal operation. NO : The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.

Pinpoint Test E: The Charging System Warning Indicator is Off With the Ignition Switch in the RUN Position and the Engine Off

Refer to SYSTEM WIRING DIAGRAMS article, Charging System for schematic and connector information.

Under normal operation, the charging system warning indicator is on with the key ON and the engine off.

Possible Causes

1. Instrument cluster
2. Powertrain control module (PCM)

1. E1 CHECK THE CHARGING SYSTEM WARNING INDICATOR OPERATION Key in OFF position. Connect the diagnostic tool. Key in ON position. Enter the following diagnostic mode on the diagnostic tool: Active Commands Using Active Commands, turn on the charging system warning indicator in the instrument cluster. Is the charging system warning indicator on? YES : Go to E2 . NO : REFER to «INSTRUMENT CLUSTER»(/lincoln/town-car/iii-2003-2011/remont/gauges-instrument-panels/#instrument-cluster-system) article to diagnose the charging system warning indicator.
2. E2 CHECK FOR CORRECT PCM OPERATION Key in OFF position. Disconnect all of the PCM connectors. Check for: corrosion. pushed-out pins. Connect all of the PCM connectors and make sure they seat correctly. Operate the system and verify the concern is still present. Is the concern still present? YES : INSTALL a new PCM. REFER to «ELECTRONIC ENGINE CONTROLS»(/lincoln/town-car/iii-2003-2011/remont/removal-installation/#electronic-engine-controls) article. REPEAT the self-test. TEST the system for normal operation. NO : The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.

Pinpoint Test F: The Generator is Noisy

Refer to SYSTEM WIRING DIAGRAMS article, Charging System for schematic and connector information.

The generator is belt-driven by the engine accessory drive system.

Possible Causes

1. Loose bolts/brackets
2. Drive belt
3. Generator/pulley

1. F1 CHECK FOR ACCESSORY DRIVE NOISE AND MOUNTING BRACKETS Key in OFF position. Check the accessory drive belt for damage and correct installation. Refer to «ACCESSORY DRIVE»(/lincoln/town-car/iii-2003-2011/remont/accessory-drive-belts/#accessory-drive-system) article. Check the accessory mounting brackets and the generator pulley for looseness or misalignment. Is the accessory drive OK? YES : Go to F2 . NO : REPAIR as necessary. TEST the system for normal operation.
2. F2 CHECK THE GENERATOR FOR EXCESSIVE ELECTRICAL NOISE Disconnect: Generator C102b Key in START position. With the engine running, determine if the generator is still noisy. Is the noise still present? YES : Go to F3 . NO : INSTALL a new generator. REFER to «GENERATOR AND REGULATOR»(/lincoln/town-car/iii-2003-2011/remont/charging-system/#charging-system-generator-regulator) article. TEST the system for normal operation.
3. F3 CHECK THE GENERATOR FOR MECHANICAL NOISE Turn off all of the accessories. With the engine running, use a stethoscope or equivalent listening device to probe the generator for unusual mechanical noise. Is the generator the noise source? YES : INSTALL a new generator. REFER to «GENERATOR AND REGULATOR»(/lincoln/town-car/iii-2003-2011/remont/charging-system/#charging-system-generator-regulator) article. TEST the system for normal operation. NO : REFER to «ENGINE SYSTEM - GENERAL INFORMATION»(/lincoln/town-car/iii-2003-2011/remont/mechanical/#engine-system-general-information) article to diagnose the source of the engine noise.

Pinpoint Test G: Radio Interference

Refer to SYSTEM WIRING DIAGRAMS article, Charging System for schematic and connector information.

The generator radio suppression equipment reduces interference transmitted through the speakers by the vehicle electrical system.

Possible Causes

1. Generator
2. Wiring/routing
3. In-vehicle entertainment system

1. G1 VERIFY THE GENERATOR IS THE SOURCE OF THE RADIO INTERFERENCE NOTE: If the original equipment manufactured (OEM) audio unit has been replaced with an aftermarket unit, the vehicle may not pass this test. Return the vehicle to OEM condition before following this pinpoint test. Start and run the engine. Tune the audio unit to a station where the interference is present. Key in OFF position. Disconnect: Generator C102b Key in START position. With the engine running, determine if the interference is still present. Is the interference present with the generator disconnected? YES : REFER to «INFORMATION AND ENTERTAINMENT SYSTEMS»(/lincoln/town-car/iii-2003-2011/remont/entertainment-systems/#information-and-entertainment-systems) article for diagnosis and testing of the in-vehicle entertainment system. NO : INSTALL a new generator. REFER to «GENERATOR AND REGULATOR»(/lincoln/town-car/iii-2003-2011/remont/charging-system/#charging-system-generator-regulator) article. TEST the system for normal operation.

Battery - Drain Testing

Note. A periodic pulsing of up to 80 milliamps (mA) or 0.080 amp draw is caused by the integrated control panel (ICP) and should be considered normal. However, no factory-equipped vehicle should have more than a 50 mA (0.050 amp) continuous draw.

Note. Many electronic modules draw 10 mA (0.010 amp) or more continuously.

Note. Use an in-line ammeter between the negative battery post and its respective cable.

Note. Typically, a drain of approximately one amp can be attributed to an engine compartment lamp, glove compartment lamp or an interior lamp staying on continually. Other component failures or wiring shorts are located by selectively pulling fuses to pinpoint the location of the current drain. When the current drain is found, the meter reading falls to an acceptable level. If the drain is still not located after checking all of the fuses, it is due to the generator.

Note. To accurately test the drain on a battery, an in-line ammeter must be used. Use of a test lamp or voltmeter is not an accurate method due to the number of electronic modules.

Check for current drains on the battery in excess of 50 mA (0.050 amp) with all of the electrical accessories off and the vehicle at rest for at least 40 minutes. Current drains can be tested with the following procedure

1. Make sure the battery junction box (BJB) and the central junction box (CJB) are accessible without turning on the interior or the underhood lights.
2. Drive the vehicle at least 5 minutes and over 48 km/h (30 mph) to turn on and activate the vehicle systems.
3. Allow the vehicle to sit with the key OFF for at least 40 minutes to allow the modules to time out/power down.
4. Connect a fused (10A) jumper wire between the negative battery cable and the negative battery post to prevent the modules from resetting and to catch capacitive drains.
5. Disconnect the negative battery cable from the negative battery post without breaking the connection of the jumper wire.
6. Connect the battery tester between the negative battery cable and the post. The meter must be capable of reading milliamps and should have a 10 amp capability.
7. Remove the jumper wire.
8. Note the amperage draw.
9. If the draw is found to be excessive, remove the fuses from the CJB one at a time and note the current reading. Do not reinstall the fuses until you have finished testing. To correctly isolate each of the circuits, all of the fuses may need to be removed and install one fuse, note the amperage draw, then remove the fuse and install the next fuse, until all of the circuits are checked. When the current level drops to an acceptable level after removing a fuse, the circuit containing the excessive draw has been located.
10. If the current draw is still excessive, remove the fuses from the BJB one at a time and note the current drop. Do not reinstall the fuses until you have finished testing. To correctly isolate each of the circuits, all of the fuses may need to be removed and install one fuse, note the amperage draw, then remove the fuse and install the next fuse, until all of the circuits are checked. When the current level drops to an acceptable level after removing a fuse, the circuit containing the excessive draw has been located.
11. Check the «SYSTEM WIRING DIAGRAMS»(ref-252473) article for any circuits that run from the battery without passing through the BJB/CJB. If the current draw is still excessive, disconnect these circuits until the draw is found. Also, disconnect the generator electrical connections if the draw can not be located. The generator may be internally shorted, causing the current drain.

Generator On-Vehicle Tests

Note. Battery posts and cable clamps must be clean and tight for accurate meter indications.

Note. Refer to the battery tester manual for complete directions for testing the charging system.

1. Turn off all of the lamps and the electrical components.
2. Place the transmission in NEUTRAL and apply the parking brake.
3. Carry out the Load Test and the No Load Test according to the following component tests

Generator On-Vehicle Tests - Load Test

1. Switch the tester to the ammeter function.
2. Connect the positive and negative leads of the tester to the corresponding battery terminals.
3. Connect the current probe to the generator B+ output terminal, circuit 2037 (RD).
4. With the engine running at approximately 2,000 RPM, adjust the tester load bank to determine the output of the generator. The generator output should be greater than the graph shown below. If not, refer to the pinpoint test or Go to «Symptom Chart»(/lincoln/town-car/iii-2003-2011/remont/charging-system/#charging-system-general-information) .

Generator On-Vehicle Tests - No Load Test

1. Switch the tester to the voltmeter function.
2. Connect the voltmeter positive lead to the generator B+ output terminal, circuit 2037 (RD) and the negative lead to ground.
3. Turn all of the electrical accessories off.
4. With the engine running at approximately 2,000 RPM, check the generator output voltage. The voltage should be between 13.2 and 15.5 volts. If not, refer back to the pinpoint test or Go to «Symptom Chart»(/lincoln/town-car/iii-2003-2011/remont/charging-system/#charging-system-general-information) .

See also:
• BATTERY, MOUNTING AND CABLES
• MODULE COMMUNICATIONS NETWORK
• MULTIFUNCTION ELECTRONIC MODULES
• Introduction - Gasoline Engines
• INSTRUMENT CLUSTER
• GENERATOR AND REGULATOR
• ELECTRONIC ENGINE CONTROLS
• ACCESSORY DRIVE
• ENGINE SYSTEM - GENERAL INFORMATION
• INFORMATION AND ENTERTAINMENT SYSTEMS
• POWERTRAIN CONTROL MODULE (PCM) DIAGNOSTIC TROUBLE CODE (DTC) INDEX
• Pinpoint Test C
• Pinpoint Test A
• Pinpoint Test B
• Pinpoint Test D
• Pinpoint Test E
• Pinpoint Test F
• Pinpoint Test G