Preliminary Checks

Battery: Check for weak or bad battery. See Battery Section. Battery must be fully charged for following electrical tests.

Wiring: Check for corroded or loose connections in charging circuit. Rectifier-regulator base must have a good, clean, tight connection for proper grounding.

If the preliminary inspection shows components to be in good condition, make the following electrical checks:

Regulating Voltage Check: (See Figures 5-15 and 5-16.) Connect an ammeter in series with the alternator output. Connect load rheostat (carbon pile) and voltmeter across battery. Check regulating voltage while running engine at 3600 rpm.

Adjust load rheostat (or carbon pile) to 3.5 amperes output. The voltage readings then should conform to the values given by the curves shown in Figure 5-17 at the temperature measured at the time of testing. For example, if the air temperature was +75°F, the upper voltage (from upper curve) would be 15.0 volts and the lower voltage (from lower curve) would be 13.8 volts.

Output Check: Run engine at 2000 rpm and adjust load rheostat (carbon pile) to obtain a constant 13.0 volts. The alternator output current should be 14 amperes minimum.

Figure 5-15. Test Arrangement with Individual Components
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