817427 30 Mercury SCREW

Most of the tests of the electrical system can be done on the engine. The wiring insulation must be in good condition. The wire and cable connections must be clean and tight. The battery must be fully charged. If the on-engine test shows a defect in a component, remove the component for more testing.The service manual Testing And Adjusting Electrical Components, REG00636 has complete specifications and procedures for the components of the starting circuit and the charging circuit.
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4C-4911 Battery Load Tester
The 4C-4911 Battery Load Tester is a portable unit in a metal case. The 4C-4911 Battery Load Tester can be used under field conditions and under high temperatures. The tester can be used to load test all 6, 8, and 12 Volt batteries. This tester has two heavy-duty load cables that can easily be fastened to the battery terminals. A load adjustment knob is located on the top of the tester. The load adjustment knob permits the current that is being drawn from the battery to be adjusted to a maximum of 1000 amperes. The tester is cooled by an internal fan that is automatically activated when a load is applied.The tester has a built-in LCD. The LCD is a digital voltmeter. The LCD is a digital meter that will also display the amperage. The digital voltmeter accurately measures the battery voltage at the battery. This measurement is taken through tracer wires that are buried inside the load cables. The digital meter, that displays the amperage, accurately displays the current that is being drawn from the battery which is being tested.Note: Refer to Operating Manual , SEHS9249 for more complete information for the use of the 4C-4911 Battery Load Tester.
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8T-0900 Ammeter
The 8T-0900 Ammeter is a completely portable, self-contained instrument that allows electrical current measurements to be made without breaking the circuit or without disturbing the insulation on the conductors. A digital display is located on the ammeter for reading current directly in a range from 1 to 1200 amperes. If an optional 6V-6014 Cable is connected between this ammeter and one of the digital multimeters, a current reading of less than 1 amperes can be read directly from the display of the multimeter.A lever is used to open the jaws over the conductor up to a diameter of 19 mm (0.75 inch). The spring loaded jaws are then closed around the conductor for the measurement of current. A trigger switch that can be locked on the ON or OFF position is used to turn on the ammeter. When the turn-on trigger is released, the last current is held on the display for five seconds. This allows accurate measurements to be taken in limited access areas. In these areas, the digital display is not visible to the operator. A zero control is provided for DC operation. The power for the ammeter is supplied by the batteries which are located inside the handle.Note: Refer to Special Instruction, SEHS8420 for more complete information for the use of the 8T-0900 Ammeter.
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9U-7330 Multimeter
The 9U-7330 Multimeter is a portable instrument with a digital display. This multimeter is built with extra protection against damage in field applications. The multimeter can display Pulse Width Modulation (PWM). The 9U-7330 Multimeter has an instant ohms indicator that permits the checking of continuity for fast circuit inspection. The multimeter can also be used for troubleshooting capacitors that have small values.Note: Refer to Special Instruction for complete information for the use of the 9U-7330 Multimeter. The Special Instruction is packaged with the unit.