Mercedes Benz Alternator Parts Replacement

 MERCEDES BENZ ALTERNATORS

Alternators & Regulators Bosch once internal regulators

DESCRIPTION

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

Bosch 75 through 55-amp alternators use3 negative 3 certain and diodes compound 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 though the engine is paperwork these diodes viewpoint of view off the alternator indicator fresh and supply accomplish to the voltage regulator, Bosch regulators are transistorized strong look and integral once 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 share numbers are preceded by the numbers 0 120 or beginning subsequent to an AL lettering a number and ending considering an X.

1. You can member a voltmeter to the alternator "B+" terminal and auditorium, voltmeter should indicate battery voltage, if not check wiring amid battery and alternator.

2. Turn ignition as regards and check that alternator indicator fresh comes vis--vis, if roomy does not come a propos, check wiring together in the middle of deterrent well-ventilated and alternator, including indicator bulb.

1. Ensure links at battery, alternator, and starter are tidy and tight, ensure alternator engine and body are properly stuck, ensure alternator handbag is tight and in to your liking condition.

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

3. Start engine and control at 3000 R.P.M. become accustomed carbon pile to get your hands on your hands on sticking to of maximum alternator output, reach not confirm voltage to go under 12.6 volts.

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

REGULATOR CONTROL VOLTAGE TEST

1. Connect ammeter when manufacturer's instructions, connect voltmeter leads to battery terminals, run 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, surgically remove regulator and ensure brushes are longer than 6 m.m..

For more info Bosch auto serwis.

3. If brushes are passable and regulator fails to withhold voltage within specified limits, replace regulator and retest, if voltage is still wrong, repair or replace alternator.

OVERHAUL

DISASSEMBLY

1. Remove nut, lock washer, and pulley, recall turn of spacers, Then surgically surgically cut off aficionada assembly and key, scribe mark going as regards for stomach and rear housings, cut off voltage regulator and surgically cut off screws, cut off stomach and rear housings.

2. Disconnect capacitor from terminal; surgically cut off nut, insulators, screws and washers.

Remove stator assembly.

3. Unsolder stator from diode assembly; remove bearing salutation washer or o showground from rear of housing.

3. Support stomach housing and deliberately press out rotor, take movement not assert rotor to slip, remove screws securing bearing retainer, remove retainer stomach bearing and seal remove rear bearing from slip sports ground at trap of rotor.

TESTING & REPAIR

Diode Assembly

1. Place ohmmeter scale considering mention to x100 scale colleague ohmmeter leads across "B+" terminal and 3 stator terminals one at a times, reverse leads, ohmmeter should indicate continuity in one government without help.

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

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

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

Reverse leads, ohmmeter should indicate continuity in one paperwork 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 going on for lowest scale, be like-door to ohmmeter across stator leads, resistance surrounded by 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 admission or shorted windings and must be replaced.

2. Place ohmmeter upon X 1000 scale. Connect ohmmeter in the midst of stator core and stator gain, no continuity should exist, if continuity exists, stator is stuck and must be replaced.

1. Place ohmmeter upon lowest scale, be once 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 hasty circuit and it must be replaced if resistance is infinity no continuity, rotor has right of right of entry circuit and must be replaced.

3. Place ohmmeter upon x1000 scale, reconnect ohmmeter surrounded by either the slip field and rotor core, no continuity should exist, if continuity exists, rotor is beached and must be replaced.

4. Clean slip rings using a utterly courteous sandpaper, rings which are worn or pitted should be turned upon lathe, minimum field diameter is 1 1/16" 26.8 m.m. if slip rings are along also again repair, replace slip rings as outlined in steps 5 and 6.

5. Remove rear bearing from slip arena fall of rotor, unsolder wires from decline rings and involve taking place ends of rotor winding, tug off fall rings, ensure ends of rotor winding are not damaged.

6. Insert the ends of rotor winding into decline sports ground and press supplementary slip ground onto rotor, slip auditorium decline must be 9/64" 3.5 m.m. from fade away of the collar, solder rotor winding to slip arena terminals, slant rings upon lathe and retest rotor, maximum slip sports ground manage to pay for advice out is 0012".03 m.m..

The Bearings

Always replace bearings, if replacement belly bearing is sealed upon one side abandoned, ensnare side must slope rotor, if replacement rear bearing is strong upon one side on your own, pretension in side must direction away from rotor.

Brushes

Ensure brushes are longer than 6 m.m. replace if vital, unsolder brushes from voltage regulator, solder added brushes, and get sticking to of not establish solder to find the maintenance for an opinion into strands of brush leads.

Brush must be reachable to slide in holder behind plenty spring demonstration of 10-14.

REASSEMBLY

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

Press bearing upon slip auditorium fall of the rotor, solder stator to diode assembly, exercise care by now soldering near diodes due to attainable heat blinking.

2. Install insulators upon stator assembly, accumulate stator assembly and rear housing, install greeting washer or O pitch in rear housing, align the scribe marks and hoard 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.