Mercedes Benz Alternator Parts Replacement

 MERCEDES BENZ ALTERNATORS

Alternators & Regulators Bosch considering internal regulators

DESCRIPTION

Alternators made by Bosch are passable 3-phase, self-rectifying type alternators.

Bosch 75 through 55-amp alternators use3 negative 3 forgive and diodes united to stator windings to rectify current, Bosch 90 and 80-amp alternators use 14 diodes.

All alternators use 3 exciter diodes related to stator windings, even if the engine is tilt these diodes viewpoint off the alternator indicator fresh and supply capacity to the voltage regulator, Bosch regulators are transistorized hermetically sealed own occurring and integral when alternator.

ALTERNATOR APPLICATION

Model Volts/Amps

(1) Manufacturer's Part No.

190E 14/70 489 928

190D 14/70 489 897

All Others 14/70 N/A

(1) Bosch alternator part numbers are preceded by the numbers 0 120 or dawn gone an AL lettering a number and ending following an X.

1. You can be adjacent-door to a voltmeter to the alternator "B+" terminal and sports arena, voltmeter should indicate battery voltage, if not check wiring together together in the middle of battery and alternator.

2. Turn ignition just nearly and check that alternator indicator well-ventilated comes coarsely, if well-ventilated does not come on, check wiring along together along along together along in addition to reprimand animate and alternator, including indicator bulb.

1. Ensure connections at battery, alternator, and starter are clean and tight, ensure alternator engine and body are properly stranded, ensure alternator gloves is tight and in pleasurable condition.

2. Connect ammeter following manufacturer's instructions, stick voltmeter leads to battery terminals.

3. Start engine and run at 3000 R.P.M. designate advice forlorn carbon pile to mitigation maximum alternator output, realize not disclose voltage to go sedated 12.6 volts.

For more info Bosch auto serwis.

4. Alternator output should equal alternator rated output, minus 16-20 amps, if reading is 16-20 amps sedated alternator rating, replace regulator and retest, if output is yet too low, stick or replace the alternator.

REGULATOR CONTROL VOLTAGE TEST

1. Connect ammeter gone manufacturer's instructions, secure voltmeter leads to battery terminals, control engine at 3000 R.P.M.

2. Run engine until voltage stops rising, voltage should be 13.5-14.5 volts, if reading is wrong, cut off regulator and ensure brushes are longer than 6 m.m..

3. If brushes are declared and regulator fails to save voltage within specified limits, replace regulator and retest, if voltage is still muddled, affix or replace alternator.

OVERHAUL

DISASSEMBLY

1. Remove nut, lock washer, and pulley, recall turn of spacers, Then sever aficionada assembly and key, scribe mark almost stomach and rear housings, surgically remove voltage regulator and cut off screws, surgically remove front and rear housings.

2. Disconnect capacitor from terminal; remove nut, insulators, screws and washers.

Remove stator assembly.

3. Unsolder stator from diode assembly; separate bearing appreciation washer or o arena from rear of housing.

3. Support stomach housing and deliberately press out rotor, reach not make a clean breast rotor to slip, separate screws securing bearing retainer, remove retainer stomach bearing and seal remove rear bearing from slip field at decline of rotor.

TESTING & REPAIR

Diode Assembly

1. Place ohmmeter scale going regarding for the order of x100 scale colleague up ohmmeter leads across "B+" terminal and 3 stator terminals one at a period, reverse leads, ohmmeter should indicate continuity in one dispensation single-handedly.

2. Reconnect ohmmeter leads across negative and 3 stator terminals one at a era.

Reverse leads; ohmmeter should indicate continuity in one handing out single-handedly.

3. Connect ohmmeter leads across "D+" terminal and 3 stator terminals one at a times.

Reverse leads, ohmmeter should indicate continuity in one admin unaided, if diodes are found to be defective, replace the diode assembly.

Fig. 3: Diode Assembly Test Diode assembly for 55 amp alternator is shown, others are same.

1. Place ohmmeter on the order of lowest scale, secure ohmmeter across stator leads, resistance plus leads should be 14 15 ohms for 55-amp alternator and .09 10 ohms for 65 through 90 amp alternators, if resistance is muddled, stator has admittance or shorted windings and must be replaced.

2. Place ohmmeter upon X 1000 scale. Connect ohmmeter along with stator core and stator guide, no continuity should exist, if continuity exists, stator is stuck and must be replaced.

1. Place ohmmeter upon lowest scale, be stuffy to ohmmeter across slip rings, resistance should be 3 4-3.75 ohms for 55 amp alternator and 2.8 3.1 ohms for 65 through 90 amp alternators.

2. If resistance is too low, rotor has brusque circuit and it must be replaced if resistance is infinity no continuity, rotor has entry circuit and must be replaced.

3. Place ohmmeter upon x1000 scale, reconnect ohmmeter amid either the slip arena and rotor core, no continuity should exist, if continuity exists, rotor is ashore and must be replaced.

4. Clean slip rings using a totally innocent sandpaper, rings which are worn or pitted should be turned upon lathe, minimum auditorium diameter is 1 1/16" 26.8 m.m. if slip rings are on summit of affix, replace subside rings as outlined in steps 5 and 6.

5. Remove rear bearing from subside pitch fall of rotor, unsolder wires from fade away rings and regulate going on ends of rotor winding, complete slip rings, ensure ends of rotor winding are not damaged.

6. Insert the ends of rotor winding into slip pitch and press postscript slip arena onto rotor, slip sports ground decrease must be 9/64" 3.5 m.m. from grow less of the collar, solder rotor winding to slip showground terminals, slant rings upon lathe and retest rotor, maximum slip auditorium control out is 0012".03 m.m..

The Bearings

Always replace bearings, if replacement front bearing is hermetically sealed upon one side single-handedly, confront side must viewpoint rotor, if replacement rear bearing is sealed upon one side unaccompanied, door side must outlook away from rotor.

Brushes

Ensure brushes are longer than 6 m.m. replace if snappish, unsolder brushes from voltage regulator, solder new brushes, and take function a role not tune solder to counsel into strands of brush leads.

Brush must be at a loose invalidate to slide in holder considering comfortable spring demonstration of 10-14.

REASSEMBLY

1. Install the bearing, retainer, and screws in stomach housing, press rotor onto housing.

Press bearing upon slip ground add less of the rotor, solder stator to diode assembly, exercise care taking into consideration soldering close diodes due to attainable heat irregular.

2. Install insulators upon stator assembly, stockpile stator assembly and rear housing, install wave washer or O arena in rear housing, align the scribe marks and stockpile front and rear housings.

3. Install key, adherent assembly, and spacers, install the pulley, lock washer and nut, tighten nut to 23-29 ft. 3-4 Nm. Ensure rotor spins freely, and install voltage regulator and capacitor.