Figure 5-17. Regulating Voltage

Check Stator and Rotor:

Make resistance checks. The coil resistance should check 0.2 to 0.4 (very low) across the contacts of the plug with an accurate ohmmeter. If found to be either open or shorted, the unit is defective. Also using an ohmmeter, check each pin to ground. There should be no continuity to ground (open circuit) as indicated by a reading of 1/2 megohm minimum.

Check AC output voltage with an au voltmeter, it snouiu ue 19 to 26 volts per 1000 rpm. If there are shorted turns, the voltage will be reduced.

If the above checks are unsatisfactory, stator and rotor should be disassembled and checked for physical damage. As a final check, substitute components known to be good and check again. If the substituted units perform okay, the original units probably were defective.

Check the Rectifier-Regulator:

If the rectifier-regulator appears to be the defective component, check it by replacing it with a unit that is known to be good and check again. Electrically disconnect the unit to be checked, then temporarily connect in the new unit. If the output is now okay, the original rectifier-regulator was defective and should be replaced. If the output is still unsatisfactory, the original unit was probably okay and the problem lies elsewhere.


This alternator is taken apart, checked, and put back together in basically the same way as the previous 1975 and earlier units, with the following exception: stator plastic magnet ring must be pushed back into stator before remounting and must be flush or below the outside rim of the shell.

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