1985 OMC 65, 100 and 155 HP Models Commercial Service Manual, PN 507450-D, Page 351Get this manual
Alternator Stator Test65 Tiller and Remote Electric Start, 100 Manual Tilt Models 1To check stator windings, disconnect the yellow lead and yellowgrey lead at the terminal blockConnect the red meter lead to either yellow lead or yellowgrey lead, and meter black lead to ground to check for shortsAn infinite reading on HI ohms scale indicates the windings are not shorted to ground2Connect the ohmmeter (LO ohms scale) between the yellow and yellowgrey leadsSee Stator ResistanceModel 65 Amp 100 Amp Stator Resistance
Rectifier Diode Test65 Tiller and Remote Electric Start, 100 Manual Tilt Models
To check the diodes, place an ohmmeter in the "HI" ohms positionThis is basically continuity testA test light may be used in place of meterUnder no circum stances use any test meter or instrument with more than 12volt source1Disconnect rectifier leads from terminal boardConnect one ohmmeter (H ohms scale) lead to either yellow or yellowgrey rectifier lead, and other meter lead to groundNote meter reading2Reverse test leads, or press polarity button if meter is so equipped, and again note meter readingAn infinite (very high) reading in both checks indicates the diode is openA zero reading in both checks indicates the diode is shortedA normal diode will show reading in one direction and no reading in the other direction3Repeat this procedure with the other rectifier yellow lead-