Alternator - Bosch Dodge Aries I

DESCRIPTION

The charging system consists of an alternator, internal voltage regulator, battery and connecting wires. The alternator has sixteen built-in rectifiers, that convert A.C. current into D.C. current. Current at output terminal is D.C. Alternator main components are rotor, stator, rectifiers, end shields and drive pulley.

The internal electronic voltage regulator is compact and is built into the rear housing of the alternator. This unit regulates vehicle electrical system voltage by limiting output voltage generated by alternator. The regulator has no moving parts and requires no adjustment after set at factory. This unit also has ability of its control circuit to vary regulated system voltage up or down as temperature changes.

Note. For Charging Circuit Diagnosis Guide, See CHRYSLER CORP. ALTERNATORS article for RWD models.

TROUBLE SHOOTING

Note. See the TROUBLE SHOOTING - BASIC PROCEDURES article in the GENERAL TROUBLE SHOOTING section.

Scheme 2

1. Check battery for full charge, recharge or replace before performing test. Disconnect negative battery cable from battery. Disconnect "BAT" lead at alternator output terminal. (Scheme 2) (Scheme 2): Test Meter Connections for Charging Circuit Resistance Test Disconnect negative battery cable before connecting test equipment.
2. Connect D.C. ammeter set to 0-100 amp scale, in series between alternator "BAT" terminal and disconnected "BAT" lead wire. Connect ammeter positive lead to "BAT" terminal and negative lead to "BAT" lead.
3. Connect positive lead of voltmeter (range 0-18 volts minimum) to "BAT" lead wire. Connect negative voltmeter lead to positive battery post.
4. Connect tachometer to engine and reconnect negative battery cable. NOTE: Be sure carbon pile rheostat is in "Open" or "Off" position before connecting leads.
5. Connect variable carbon pile rheostat across negative and positive terminals of battery.
6. Start engine and maintain engine speed at idle. Adjust engine speed and carbon pile rheostat to obtain 20 amps flowing in circuit. Observe voltmeter reading. Reading should not exceed.5 volts.
7. If voltmeter reading was more than.5 volts, inspect, clean and tighten all connections in charging circuit. A voltage drop test may be performed at each connection to locate connection with excessive resistance.
8. If voltmeter reading was okay, turn engine off and disconnect all test equipment.

Scheme 3

1. Check battery for full charge, recharge or replace before performing test. Disconnect negative battery cable from battery. Disconnect "BAT" lead at alternator output terminal. (Scheme 3) (Scheme 3): Test Meter Connections for Alternator Current Output Test Before testing, be sure battery has full charge.
2. Connect D.C. ammeter set to 0-100 amp scale, in series between alternator "BAT" terminal and disconnected "BAT" lead wire. Connect ammeter positive lead to "BAT" terminal and negative lead to "BAT" lead.
3. Connect positive lead of voltmeter (range 0-18 volts minimum) to "BAT" terminal on alternator. Connect negative lead of voltmeter to good ground. Connect tachometer and reconnect negative battery cable. NOTE: Be sure carbon pile rheostat is in "Open" or "Off" position before connecting leads.
4. Connect variable carbon pile rheostat between battery terminals. Start engine and immediately reduce engine speed to idle.
5. Adjust carbon pile rheostat and engine speed, in small increments, to specified speed and check output current. See Specification Chart. CAUTION: DO NOT allow voltage meter to read above 16 volts.
6. Ammeter reading must be within limits shown in chart. If reading is less than specified, alternator should be removed and bench tested.

Note. Battery specific gravity should be above 1.220 for a proper regulated voltage check. Charge battery or use a good test battery before testing regulator. DO NOT leave uncharged battery in circuit.

Scheme 4

1. Check battery for full charge, recharge or replace before performing test. Clean battery terminals. Turn ignition switch OFF.
2. Disconnect "BAT" lead wire at alternator output terminal. Connect ammeter (Range 0-100 amps minimum) in series between alternator "Bat B+" terminal and disconnected "BAT" lead wire.
3. Connect positive lead to disconnected "BAT" terminal and negative lead to disconnected "BAT" lead.
4. Connect positive lead of voltmeter (range 0-18 volts minimum) to "BAT B+" terminal of alternator. Connect negative lead of voltmeter to ground. (Scheme 4) (Scheme 4): Test Meter Connections for Internal Voltage Regulator Test Check that voltage readings are in accordance with voltage chart.
5. Check voltmeter for zero reading. If pointer of voltmeter deflects (voltage is present), defective alternator is suspected.
6. Turn ignition switch to "ON" ( DO NOT start engine). Voltmeter reading should be within one half volt of battery voltage. Connect tachometer to engine. NOTE: Ensure that when engine is started, NO starting current is applied to ammeter.
7. With test ammeter terminals short-circuited, start engine. Remove short circuit across test ammeter terminals and increase engine speed immediately to 2,000 to 3,000 RPM. Record ammeter reading.
8. If test ammeter reading is 10 amps or less, take voltage reading without changing engine speed. This reading is charging voltage. NOTE: Since electronic voltage regulator is temperature compensation type, charging voltage varies with temperature. Thus, temperature around rear bracket of alternator must be measured and charging voltage corrected for temperature.
9. If ammeter reading is more than 10 amps, continue to charge battery until reading falls. An alternative method is to limit engine charging current by connecting 1/4 ohm (25W) resistor in series with battery. Disconnect all test equipment and connect battery cable.

Slip Rings

1. Inspect outside circumference of slip rings for dirt or roughness. If necessary, clean or polish slip rings with fine sandpaper.
2. If slip rings are badly worn or roughened, rotor assembly must be replaced. Slip rings are not serviced as a separate item. They are serviced with rotor assembly.

Scheme 5

Scheme 6

1. To check for open field coil, connect ohmmeter to slip rings. Ohmmeter reading should be between 1.5 and 2.0 ohms on rotor coils at ambient temperature. (Scheme 5) (Scheme 5): Ohmmeter Hookup for Testing Rotor Field Coils Worn or rough slip rings require rotor replacement. NOTE: Resistance between 2.5 and 3.0 ohms would result from alternator rotors that have been operated on vehicle at higher engine compartment temperatures. Readings above 3.5 ohms would indicate high resistance rotor coils and further testing or replacement may be required.
2. To check for shorted field coil, connect ohmmeter to both slip rings. If reading is below 1.5 ohms, field coil is shorted. To check rotor for grounded field coil, connect ohmmeter from each slip ring to rotor shaft. (Scheme 6) (Scheme 6): Ohmmeter Hookup for Testing Rotor for Ground Continuity between slip rings and core means rotor is grounded.
3. The ohmmeter should read infinite. If reading is zero or higher, rotor is grounded. Replace rotor assembly.

STATOR ASSEMBLY

1. To test stator for open circuit, check for continuity between leads of stator coil. Connect ohmmeter leads to each of three stator lead terminals, one at a time.
2. Continuity should exist between all stator lead terminals. If there is no continuity, stator coil is defective. Replace stator assembly.
3. To test stator for ground, Connect one ohmmeter lead to stator coil frame. Connect other ohmmeter lead to each stator coil lead terminal. There should be no continuity. If continuity exists, stator is grounded. Replace stator assembly.

Scheme 7

1. To test inner brush circuit, connect one ohmmeter lead to inner brush. Connect other ohmmeter lead to inner brush terminal. (Scheme 7) Continuity should exist. If continuity does not exist, replace brush assembly. (Scheme 7): Ohmmeter Hookup for Testing Outer Brush Circuit Test inner circuit with probes on inner brush and terminal.
2. To test outer brush circuit, connect one ohmmeter lead to outer brush. Connect other ohmmeter lead to outer brush terminal. (Scheme 7) Continuity should exist. If continuity does not exist, replace brush assembly.

RECTIFIER ASSEMBLY

Note. If rectifiers test shorted, unsolder stator from rectifier assembly and retest. Use a pair of needle nose pliers as a heat sink during any soldering operations. It is possible that a stator winding could be grounded to stator laminations or rectifier end shield which would indicate shorted negative rectifier.

Scheme 8

1. Connect one ohmmeter lead to positive heat sink. Connect other ohmmeter lead to each of positive rectifier pins and test for continuity. Reverse ohmmeter leads and retest. (Scheme 8) (Scheme 8): Rectifier Assembly Showing Test Points (Viewed from Front) Rectifier connections should have continuity in one direction only.
2. There should be continuity in only one direction. If there is continuity in both directions, rectifier is short-circuited. If there is no continuity in either direction, rectifier is open. If rectifier is shorted or open, replace rectifier assembly.

Negative Rectifier

1. Connect one ohmmeter lead to negative heat sink. Connect other ohmmeter lead to each of negative rectifier pins and test for continuity. (Scheme 8) Reverse ohmmeter leads and retest.
2. There should be continuity in only one direction. If there is continuity in both directions, rectifier is shorted. If there is no continuity is either direction, rectifier is open. If rectifier is either shorted or open, replace rectifier assembly.

Scheme 9

1. With alternator removed, place alternator assembly mounting lug in a soft-jawed vise. Loosen pulley nut and remove lock washer. (Scheme 9) (Scheme 9): Exploded View of Alternator With Internal Regulator Check alternator for proper output. If not to specifications, disassemble and retest.
2. Remove alternator pulley, pulley-to-fan spacer and pulley fan. Remove woodruff key from rotor shaft. Disconnect capacitor terminal, remove capacitor mounting screw and capacitor.
3. Remove voltage regulator and brush holder mounting screw. Remove regulator and brush holder. Remove "D+" stud nut, lock washer, stud washer and stud insulators. Remove battery stud nut, lock washer, flat washer and insulator.
4. Remove through bolts. Pry between stator and drive end shield and separate drive end shield, pulley and rotor assembly away from stator and rectifier end shield assembly.
5. Press rotor out of drive end shield. Remove spacer. Remove pulley fan spacer. Remove four alternator drive end shield bearing retainer screws and bearing retainer. Press out drive end shield bearing. Remove front drive bearing from front drive end shield. NOTE: Use a pair of needle nose pliers as a heat sink during any soldering operations.
6. Unsolder stator-to-rectifier leads. Scribe line on stator coil frame. Remove stator from rectifier end shield assembly. Remove three rectifier assembly mounting screws and remove stator assembly.
7. Remove inner battery stud insulator. Remove "D+" stud insulator, stud nut, stud flat washer and insulating washer. Remove rear bearing oil and dust seal. Check rotor bearing surface for scoring. Remove rear rotor bearing with puller (C-4068 or C-4333).

Note. During cleaning and inspection, DO NOT immerse stator field coil assembly, rotor assembly or rectifier assembly in cleaning solvent. Immersing these assemblies will damage parts. Clean with moist cloth only and wipe dry.

REASSEMBLY

1. To reassemble, reverse disassembly procedures and note the following
2. When assembling rotor bearing, press bearing onto shaft until inner race bottoms against shoulder.
3. When assembling stator to rectifier end shield assembly, align scribe marks. Turn pulley by hand to ensure that no parts contact or bind with each other.
4. After assembly, install alternator and adjust drive belt tension. Tighten alternator pivot bolt and anchor nut to 40 ft. lbs. (54 N.m). Start engine and retest alternator current output.

SPECIFICATIONS

BOSCH ALTERNATOR SPECIFICATIONS

See also:
• TROUBLE SHOOTING - BASIC PROCEDURES