Charging System - Service Information: Other Dodge Nitro I

GENERATOR RATINGS

GENERATOR

The generator is belt-driven by the engine using a serpentine type drive belt. It is serviced only as a complete assembly. If the generator fails for any reason, the entire assembly must be replaced.

As the energized rotor begins to rotate within the generator, the spinning magnetic field induces a current into the windings of the stator coil. Once the generator begins producing sufficient current, it also provides the current needed to energize the rotor.

The stator winding connections deliver the induced AC current to 3 positive and 3 negative diodes for rectification. From the diodes, rectified DC current is delivered to the vehicle electrical system through the generator battery terminal.

Although the generators appear the same externally, different generators with different output ratings are used on this vehicle. Be certain that the replacement generator has the same output rating and part number as the original unit. Refer to SPECIFICATIONS and see GENERATOR RATINGS for amperage ratings and part numbers.

Noise emitting from the generator may be caused by: worn, loose or defective bearings; a loose or defective drive pulley; incorrect, worn, damaged or misadjusted fan drive belt; loose mounting bolts; a misaligned drive pulley or a defective stator or diode.

Scheme 27

1. Disconnect and isolate negative battery cable at battery. CAUTION: Never force a belt over a pulley rim using a screwdriver. The synthetic fiber of the belt can be damaged. CAUTION: When installing a serpentine accessory drive belt, the belt MUST be routed correctly. The water pump will be rotating in the wrong direction if the belt is installed incorrectly, causing the engine to overheat. Refer to belt routing label in engine compartment, or refer to Belt Schematics in «COOLING»(ref-306154) .
2. Remove generator drive belt. Refer to «COOLING»(ref-306154) for procedures.
3. Unsnap plastic protective cover from B+ mounting stud.
4. Remove B+ terminal mounting nut at top of generator.
5. Disconnect field wire electrical connector at rear of generator by pushing on connector tab.
6. Remove four generator mounting bolts (2).
7. Remove generator (1) from vehicle.

Scheme 28

1. Disconnect and isolate negative battery cable at battery. CAUTION: Never force a belt over a pulley rim using a screwdriver. The synthetic fiber of the belt can be damaged. CAUTION: When installing a serpentine accessory drive belt, the belt MUST be routed correctly. The water pump will be rotating in the wrong direction if the belt is installed incorrectly, causing the engine to overheat. Refer to belt routing label in engine compartment, or refer to Belt Schematics in «COOLING»(ref-306154) .
2. Remove generator drive belt. Refer to «COOLING»(ref-306154) for procedures.
3. Unsnap plastic protective cover from B+ mounting stud.
4. Remove B+ terminal mounting nut at top of generator.
5. Disconnect field wire electrical connector at rear of generator by pushing on connector tab.
6. Remove one vertical generator mounting bolt (2) and two horizontal mounting bolts (3) and (4).
7. Remove generator (1) from vehicle.

Scheme 29

1. Disconnect and isolate negative battery cable at battery. CAUTION: Never force a belt over a pulley rim using a screwdriver. The synthetic fiber of the belt can be damaged. CAUTION: When installing a serpentine accessory drive belt, the belt MUST be routed correctly. The water pump will be rotating in the wrong direction if the belt is installed incorrectly, causing the engine to overheat. Refer to belt routing label in engine compartment, or refer to Belt Schematics in «COOLING»(ref-306154) .
2. Remove generator drive belt. Refer to «COOLING»(ref-306154) for procedures.
3. Unsnap plastic protective cover from B+ mounting stud.
4. Remove B+ terminal mounting nut at top of generator.
5. Disconnect field wire electrical connector at rear of generator by pushing on connector tab.
6. Remove generator mounting bolts (2) and (3).
7. Remove generator (1) from vehicle.

GENERATOR DECOUPLER

The generator decoupler is used only with certain engines. The decoupler is a one-way clutch designed to help reduce belt tension fluctuation, vibration, reduce fatigue loads, improve belt life, reduce hubloads on components, and reduce noise. Dry operation is used (no grease or lubricants). The decoupler is not temperature sensitive and also has a low sensitivity to electrical load. The decoupler is a non-serviceable item and is to be replaced as an assembly. see scheme 10

The generator decoupler is used only with certain engines.

Scheme 30

Two different type generator decoupler pulleys are used. One can be identified by the use of machined splines (3). (Scheme 30)

Scheme 31

The other decoupler is equipped with a hex opening (2) and will not use splines. (Scheme 31)

Different special tools are required to service each different decoupler. Refer to following procedure.

Scheme 32

Scheme 33

Scheme 34

Scheme 35

Scheme 36

1. Disconnect negative battery cable.
2. Remove generator and accessory drive belt. Refer to «REMOVAL»(ref-306161-S35576092952008120900000). 1 - INA DECOUPLER 2 - TOOL #8823 (VM.1048)
3. Position Special Tool #8823 (VM.1048) (2) into decoupler (1). (Scheme 32) 1 - GENERATOR SHAFT 2 - HEX
4. Determine if end of generator shaft is hex shaped (2). (Scheme 33) 1 - GENERATOR SHAFT 2 - SPLINES
5. Determine if end of generator shaft is splined (2). (Scheme 34) 1 - DEEP 10 MM SOCKET 2 - TOOL #8823 (VM.1048)
6. If hex is used, insert a 10MM deep socket (1) into tool #8823 (VM.1048). (Scheme 35) 1 - DRIVER 2 - TOOL #8823 (VM.1048) 3 - 17 MM WRENCH
7. If splined, insert a 5/16" 6-point hex driver (1), or a 10MM 12-point triple square driver into tool #8823 (VM.1048). (Scheme 36) 1 - DEEP 10 MM SOCKET 2 - TOOL #8823 (VM.1048)
8. The generator shaft uses conventional right-hand threads to attach decoupler. To break decoupler loose from generator threads, rotate end of tool (1) clockwise (Scheme 35)or rotate end of tool (1) clockwise (Scheme 35) 1 - DRIVER 2 - TOOL #8823 (VM.1048) 3 - 17 MM WRENCH
9. After breaking loose with tool, unthread decoupler by hand from generator.

Scheme 37

Scheme 38

1. Disconnect negative battery cable.
2. Remove generator and accessory drive belt. Refer to «REMOVAL»(ref-306161-S35576092952008120900000).
3. Position Special Tool #8433 into decoupler. Align to hex end of generator shaft. (Scheme 37)
4. The generator shaft uses conventional right-hand threads to attach decoupler. To break decoupler loose from generator threads, rotate end of tool clockwise. (Scheme 38)
5. After breaking loose with tool, unthread decoupler by hand from generator.

Scheme 39

Scheme 40

1. Thread decoupler pulley onto generator shaft by hand (right-hand threads).
2. Position Special Tool #8823 (VM.1048) into decoupler. 1 - 10MM DEEP SOCKET 2 - TOOL # 8823 (VM.1048)
3. Determine if end of generator shaft is hex shaped or is splined. If hex is used, insert a 10MM deep socket (1) into tool #8823 (VM.1048) (Scheme 39)or if splined, insert a 5/16" 6-point hex driver (1), or a 10MM 12-point triple square driver into tool #8823 (VM.1048) (Scheme 40) 1 - DRIVER 2 - TOOL # 8823 (VM.1048) 3 - BACKUP WRENCH
4. Do not use an adjustable, ratcheting "click type" torque wrench. Most "click type" wrenches will only allow torque to be applied in a clockwise rotation. Use a dial-type or beam-type wrench. Tighten in counterclockwise rotation and tighten to 110 N.m (81 ft. lbs.).
5. Install accessory drive belt, and generator. Refer to «INSTALLATION»(ref-306161-S23448537052008120900000).
6. Connect negative battery cable.

Scheme 41

1. Thread decoupler pulley onto generator shaft by hand (right-hand threads).
2. Position Special Tool 8433 into decoupler. Align tool to hex end of generator shaft.
3. Do not use an adjustable, ratcheting "click type" torque wrench. Most "click type" wrenches will only allow torque to be applied in a clockwise rotation. Use a dial-type or beam-type wrench. Tighten in counterclockwise rotation and tighten to 110 N.m (81 ft. lbs.).
4. Install accessory drive belt, and generator. Refer to «INSTALLATION»(ref-306161-S23448537052008120900000) .
5. Connect negative battery cable.

ELECTRONIC VOLTAGE REGULATOR

The Electronic Voltage Regulator (EVR) is not a separate component. It is actually a voltage regulating circuit located within the Powertrain Control Module (PCM). The EVR is not serviced separately. If replacement is necessary, the PCM must be replaced.

The amount of DC current produced by the generator is controlled by EVR circuitry contained within the Powertrain Control Module (PCM). This circuitry is connected in series with the generators second rotor field terminal and its ground.

Voltage is regulated by cycling the ground path to control the strength of the rotor magnetic field. The EVR circuitry monitors system line voltage (B+) and battery temperature (refer to Battery Temperature Sensor, see BATTERY SYSTEM - SERVICE INFORMATION for more information). It then determines a target charging voltage. If sensed battery voltage is 0.5 volts or lower than the target voltage, the PCM grounds the field winding until sensed battery voltage is 0.5 volts above target voltage. A circuit in the PCM cycles the ground side of the generator field up to 100 times per second (100Hz), but has the capability to ground the field control wire 100% of the time (full field) to achieve the target voltage. If the charging rate cannot be monitored (limp-in), a duty cycle of 25% is used by the PCM in order to have some generator output. Also refer to OPERATION for additional information.