Field Circuit Test

Turn ignition "ON", but do not start engine. Check voltage at slip ring by touching positive probe of voltmeter to field terminal (EX) with regulator attaching screws removed. See Fig 1.

Fig 1: Checking Field Circuit (Regulator Wire Connected)
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Voltage should not exceed 2 volts .
If voltmeter reads more than 2 volts, field circuit is defective. Examine brushes, brush leads and holder. Replace brushes if shorter than 0.15" (4 mm). If voltmeter reads zero (0) volts, check connections to regulator, ignition switch and indicator lamp.
Check regulator circuit by removing Green lead from field terminal (EX) and measuring voltage across field windings. See Fig 2. Voltage should not exceed 2 volts. If voltage is correct, proceed to OUTPUT VOLTAGE TEST . If 8-12 volts is indicated, alternator is defective.

Fig 2: Checking Regulator Circuit with Voltmeter
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Green wire must be removed from field terminal .
If voltage in step 3) was incorrect, proceed to next test.