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Testing genernator with regulator in car - ra15001405010x(5010)

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A. Pre-conditions, B. Regulating voltage, C. Charging current, D. Diodes Engines 104, 119, 120, 603, 606 in Model 140 

Operation no. of operation texts and work units or standard texts and flat rates:

  1. Preconditions for test 
    Electric wiring to battery and generator as well as grounding strap between engine and body, check that they are tight and in proper condition.
    Tension of poly V-belt check (13-3420) .
    Electrolyte density measure, specification ≥1.24 kg/dm3 .
    Charge indicator lamp check function (see table).
    Ignition/glow start switch in position Charge indicator
    0 OFF
    1 OFF
    2 ON
    COMMERCIALLY AVAILABLE TESTER

    Acidimeter e.g. Hazet
  2. Testing regulating voltage 

    Preliminary work:

    Section A. Preconditions for test

    Connection diagram

    Fig 1: Connection Diagram Of Generator
    G05438630Courtesy of MERCEDES-BENZ OF NORTH AMERICA.
    Multimeter (003) connect, disconnect.
    Engine start, switch off.
    Charge indicator Check function when idling and at increasing engine speed (up to 3000 rpm). Charge indicator lamp must go out.
    Regulating voltage Test. Run engine at 3000 rpm. Load on battery only from automatically operating components (e.g. ignition). Take reading of regulating voltage after running for 2 minutes.
    Specification:  13.0 - 14.5 volt.
    Regulating voltage >14.5 V
    1. Renew regulator.
    2. Renew generator if regulator in order.
    Regulating voltage <13.0 V
    1. Eliminate contact resistance at electrical connections of charging system.
    2. Perform diode test as per D.
    COMMERCIALLY AVAILABLE TESTER

    Multimeter e.g. Sun DMM-5 or Fluke, 23
  3. Testing charging current 

    Preliminary work:

    A. Preconditions for test

    B. Testing regulating voltage

    Connection diagram

    Fig 2: Connection Diagram Of Charging System
    G05438631Courtesy of MERCEDES-BENZ OF NORTH AMERICA.
    Multimeter (003) connect, disconnect.
    Volt/ampere tester with load resistor (079) connect, disconnect.
    Engine start, switch off.
    Charging current Test. Run engine up to appropriate speed (see table).

    Apply load to battery with load resistor until max. charging current is reached. The regulating voltage must not drop below 12.7 volts when performing this step.

    Specification (see table).

    Specification not reached. Perform diode test as per D.

    CHARGING CURRENT OF GENERATOR

    Engine Charging current 14 volt ampere Engine speed (corresponds to generator speed of 6300 rpm) Transmission ratio engine to generator
    104 120 (up to approx. 03/95) 2500 2,53
    104 115 (as of approx. 04/95) 2500 2,53
    119 120 2200 2,91(1)
    119 120 up to approx. 02/94 1950 3, 2(2)
    119 143 as of approx. 03/94 1950 3,2
    120 120 up to approx. 02/94 1950 3,2
    120 143 as of approx. 03/94 1950 3,2
    603 100 up to approx. 01/93 2200 2,89
    603 90 as of approx. 02/93 2200 2,89
    606 115 2200 2,89
    (1) With 8-groove poly V-belt
    (2) With 6-groove poly V-belt
    COMMERCIALLY AVAILABLE TESTERS

    Multimeter e.g. Sun DMM-5 or Fluke, 23
    Volt/ampere tester with load resistor e.g. Hermann, Elektronic
  4. Testing diodes 

    Connection diagram

    Fig 3: Connection Diagram Of Diodes
    G05438632Courtesy of MERCEDES-BENZ OF NORTH AMERICA.
    NOTE: It is not possible to assess the exciter diode when performing this test.
    Engine tester with oscilloscope (030) connect, disconnect.
    Engine start, switch off.
    Low beam switch on, switch off.
    Diode harmonics assess at 3000 rpm (engine speed).
    Diode harmonics in order renew regulator.
    Diode harmonics not in order renew generator.
    Fig 4: Harmonics Of Diodes In Order (Voltage Peaks Possible But Of No Significance)
    G05438633Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

    Harmonics of diodes in order (voltage peaks possible but of no significance) (example).

    Fig 5: Harmonics If Positive Diode Is Faulty
    G05438634Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

    Harmonics if positive diode is faulty (example).

    Fig 6: Harmonics If Negative Diode Is Faulty
    G05438635Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

    Harmonics if negative diode is faulty (example).

    NOTE: If problems exist with current supply, test diode matrix (TESTING THE DIODE MATRIX ).
    COMMERCIALLY AVAILABLE TESTERS

    Engine tester with oscilloscope e.g. Hermann, Datascope 980 Bosch, MOT 301/400 Sun, 2110 BEAR, DACE
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