1. Connect the voltmeter leads ... RED to the battery positive (+) terminal, BLACK to terminal "50" of the starting motor.
2. On vehicles with automatic transmission, place the lever in Park or Neutral. On vehicles with manual transmission, depress the clutch.
(NOTE: A jumper wire could be used to bypass either of these switches).
3. Crank the engine and observe the voltmeter. Less than .5 volt is acceptable. If the current draw was high or cranking speed slow, the starter motor is defective. More than .5 volt indicates excessive resistance. Isolate the trouble and correct the cause.
4. Check the neutral start switch or clutch switch for excessive voltage drop. Also check the ignition switch. Adjust or replace a defective switch, as necessary.
5. An alternate method to checking the voltage drop across each component is to leave the voltmeter connected to the battery (+) terminal and move the voltmeter negative lead back through the circuit toward the battery. The point of high resistance is found between the point where voltage drop fell within specs and the point last checked.
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