Rolls Royce 1927 20 HP can you adjust charging rate of generator mine is showing 15.5 volts and is overheating coil is there a voltage regulator on this model many thanks

DTC P1637

The powertrain control module (PCM) / engine control module (ECM) uses the charge indicator control circuit, and the generator 2 turn on signal circuit on diesels with dual generators, to control the generator(s). A high side driver within the PCM/ECM allows the PCM/ECM to turn the generator ON and OFF. When generator operation is desired, the PCM/ECM sends a 10-11 volts-volt signal to the voltage regulator via the generator turn on signal circuit. This causes the voltage regulator to begin controlling the generator field circuit. Once the generator is enabled by the PCM/ECM, the voltage regulator controls generator output independently of the PCM/ECM. Under certain operating conditions, the PCM/ECM can turn OFF the generator by turning OFF the voltage on the charge indicator control circuit. The PCM/ECM has fault detection circuitry which monitors the state of the charge indicator control circuit. If the fault detection circuit senses a voltage other than what is expected, the charge indicator will turn ON and this DTC will set. The voltage regulator also contains fault detection circuitry. If the regulator detects a problem, the regulator will ground the charge indicator control circuit, pulling the voltage low. This also causes the charge indicator to turn ON and the PCM/ECM to set the DTC.

What engine is in your truck ?

DTC P1638

The powertrain control module (PCM) uses the generator field duty cycle signal circuit to monitor the duty cycle of the generator. The generator field duty cycle signal circuit connects to the high side of the field winding in the generator. A pulse width modulated (PWM) high side driver in the voltage regulator turns the field winding ON and OFF. The PCM uses the PWM signal input to determine the generator load on the engine. This allows the PCM to adjust the idle speed to compensate for high electrical loads.
The PCM monitors the state of the generator field duty cycle signal circuit. When the key is in the RUN position and the engine is OFF, the PCM should detect a duty cycle near 0 percent. However, when the engine is running, the duty cycle should be between 5-100 percent. The PCM monitors the PWM signal using a key ON test and a RUN test. During the tests, if the PCM detects an out of range PWM signal, DTC P1638 will set. When the DTC sets, the PCM will send a class 2 serial data message to the IPC to illuminate the charge indicator.

Sorry but I am not familiar with the machine or the application.

The unit is effectively a dynamo and there is a couple of methods of regulating the output. The movable brush method is crude, inefficient and outdated which leaves a variety of two and three bobbin vibrating electromagnetic types with and without temperature compensation. Until the charge rate exceeds the battery voltage the dynamo would usually be disconnected from the battery, something that could be achieved by manual switching but is commonly the function of the first bobbin of a standard regulator, the dynamo cutout.

The second bobbin is the vibrating voltage regulator which is normally adjusted off load or in the open circuit position; disconnected from the battery and that is achieved by preventing the cutout contacts from closing with a piece of card or similar. The engine speed is raised and the adjustment carried out until the dynamo output voltage is 14.5/15.3. The former adjustment for continuous operation and the latter for short use or operating at night.

It is inevitable there will be variations and it is worth noting if the battery cannot be disconnected from the dynamo an accurate regulator adjustment cannot be made unless the battery is in good health and fully charged - 13.0/13.2 volts after standing for several hours.

It is inside the Alternator or bolted to the outside, depends on type, several were used on this year..

Running the car will drain the battery it if it's not charging ! An if your charging light is on it isn't charging ! Did you check power an grounds on the alternator ? There is a single heavier wire on the back of the alternator, this should have battery voltage ! You may want to take this to a ASE certified repair shop !
Functionality
With the ignition switch in the RUN position, voltage is applied through the warning indicator I circuit 904 (LG/RD) to the voltage regulator. This turns the regulator on, allowing current to flow from battery sense A circuit 35 (OG/LB) to the generator field coil. When the engine is started, the generator begins to generate alternating current (AC) which is internally converted to direct current (DC). This current is then supplied to the vehicle's electrical system through the output (B+) terminal of the generator.
Once the generator begins generating current, a voltage signal is taken from the generator stator and fed back to the regulator S circuit 4 (WH/BK). 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 35 (OG/LB). The A circuit 35 (OG/LB) 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 will vary with temperature and is typically higher in cold temperatures and lower in warm temperatures. This allows for better battery recharge in the winter and reduces the chance of overcharging in the summer.
Battery Positive Output (B+) Circuit 38 (BK/OG)
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 904 (LG/RD) is used to turn on the voltage regulator. This circuit is powered up with the ignition switch 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.
A Circuit 35 (OG/LB)
The A (battery sense) circuit 35 (OG/LB) is used to sense battery voltage. This voltage is used by the regulator to determine generator output. This circuit is used to supply current to the generator field (rotor). The amount of current supplied to the rotor will determine generator output.
S Circuit 4 (WH/BK)
The S (stator) circuit 4 (WH/BK) is used to feed back a voltage signal from the generator to the regulator. This voltage is used by the regulator to turn off the charging system warning indicator. The S circuit is fed back externally on external mounted regulator generators.
Visual Inspection Chart Mechanical Electrical

• Battery case, posts, hold-down clamp, cables and connections
• Generator drive (serpentine) belt for condition and tension to make sure there is no slip between the belt and the pulley. For additional information, refer to Section 303-05 .
• Battery charge
• Generator pulley

• Battery junction box (BJB)Mega Fuse
• Battery junction box fuse:
  • 11 (20A)
• Central junction box (CJB) fuse:
  • 30 (30A)
• Circuitry
• Charging system warning indicator
• Cables

1. Check the operation of the charging system warning indicator lamp (instrument cluster). Normal operation is as follows:
   • With the ignition switch OFF, the charging system warning indicator should be OFF.
   • With the ignition switch in RUN and the engine off, the charging system warning indicator light should be on.
   • With the engine running, the charging system warning indicator light should be off.

1. Verify the battery condition. Refer to Section 414-01 .

Normal Charging System Voltages and Charging System Warning Indicator Operation Ignition Switch Position A Circuit 35 (OG/LB) S Circuit 4 (WH/BK) I Circuit 904 (LG/RD) Generator B+ Circuit 38 (BK/OG) Battery Engine to Battery Ground Charging System Warning Indicator Operation OFF 12 volts 0 volts 0 volts 12 volts 12 volts 0 volts Off RUN-engine off 12 volts 0 volts 1-3 volts 12 volts 12 volts 0 volts Illuminated RUN-engine running 13-
15 volts 1/2 battery voltage 13-
15 volts 13-
15 volts 13-
15 volts 0 volts Off

1. If the customer concern is verified after the initial inspection, refer to the Symptom Chart to determine which tests to carry out.
2. • The charging system warning indicator is on with the engine running (the system voltage does not increase)
   • Circuitry.
   • Voltage regulator.
   • Generator.
   • GO to Pinpoint Test B .
   Your whole problem is the alternator is not charging , a couple tests with a volt meter would tell you !

you should have 12.5 volts with engine off at battery and 14.4v with engine running and charging system working. Is alternator light on? please rate, thx.

There are different versions and 1989 is too old to get on line. here is 1993, so take with caution. Also check the fusible link.

Battery Positive Voltage (B+) Output
The generator (alternator) output is supplied through the Battery Positive Voltage (B+) output connection to the battery and electrical system. I Circuit
The I circuit, or 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 indicator on if there is a fault in the charging system operation or associated wiring circuits A Circuit
The A circuit, or battery sense circuit, is used to sense the battery voltage. This voltage is used by the regulator to determine the output. This circuit is also used to supply power to the generator (alternator) field coil. This circuit is connected back to the load distribution point and is a protected circuit. S Circuit
The S circuit, or stator circuit, is used to feedback a voltage signal from the generator (alternator) to the regulator. This voltage, typically 1/2 battery voltage, is used by the regulator to turn off the indicator.

it should notgo over 14 1/2 volts.

Get free DTC codes scan from Autozone. I think you will get DTC code 1246 - System Voltage Malfuction.

The I (indicator) (BAT light) wire activates alternator field circuit.

The heavy B wire circuit sends current to the battery for charing and to run the car.

The S circuit helps control the amount of charge. I suspect yours is not controlling. This car has the PCM (engine computer) help control the output and turn the BAT light on when under or over charging.

SECTION 414-00: Charging System - General Information 2003 Windstar Workshop Manual
DESCRIPTION AND OPERATION Charging System This vehicle is equipped with a powertrain control module (PCM)-controlled "smart charge" charging system. The PCM-controlled charging system is a system whereby the PCM determines the optimal voltage setpoint for the charging system and communicates this information to the voltage regulator. The PCM-controlled charging system is unique in that it has two uni-directional communication lines between the PCM and the generator/regulator. Both of these communication lines are pulse-width modulated. The GEN COM line communicates the desired setpoint from the PCM to the voltage regulator and the GEN MON line communicates the alternator load condition to the PCM. The third pin on the voltage regulator, the A circuit pin, is a dedicated battery voltage sense line.
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Charging system malfunction (high or low system voltage)

possible causes:

• A circuit 35 (OG/LB).
• A circuit fuse link.
• B+ circuit 36 (YE/WH).
• B+ circuit fuse links.
• Generator.
• PCM
• GEN-COM circuit 586 (RD/PK).
• GEN-MON circuit 585 (VT).

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Generator The generator (10300) on this vehicle is monitored and controlled by the powertrain control module (PCM). The PCM monitors the voltage regulator and sends a duty cycle command back to the voltage regulator to regulate the amount of field current supplied to the generator. The generator has an internal voltage regulator. The generator and voltage regulator are installed as an assembly.
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I'll send wiring diagram tomorrow.

please rate

https://s11.postimg.org/crrcun103/generator.jpg

Click on the link.
The diagram shows generator with internal voltage regulator and with external voltage regulator, at the moment, I don't know which one you have?
The bat terminal at the generator should be hot even with the key off, is it, use a test light. If no voltage either the fusible link is faulty or the wiring circuit to battery +. You can see fusible links in diagram.
Could be other issues, the generator probably needs excite voltage or it won't work. The excite voltage comes from charge indicator circuit. Does the charge lamp on the dash work?

Yes, BUT, you better have a battery, or batteries installed in the system, that add up to 24 volts (I assume this 24 volt alternator has a built-in voltage regulator?)

If there isn't anything to 'tell' the voltage regulator, to just put out the needed voltage to keep 24 volts running smoothly, it will put out way more than that, And BURN up!

Usually when the battery light comes on it means there is a problem with the alternator. It means it is putting out less than 12.2-12.5 volts.

if no voltage check ground n power if ok check the crank sensor