1990 Johnson Evinrude "ES" Cross V 88 thru 115, 150 thru 175, P/N 507874, Page 292Get this manual
Rectifier Ohmmeter Tests88 Model
INote Disconnect
battery cables before proceeding with this
1Disconnect all rectifier leads from terminal board
2 Calibrate ohmmeter on high ohms scale and connect one
lead to clean engine groundConnect the other lead to the rectifier yellowgray leadNote the readingReverse the ohmmeter connections or press the "reverse polarity" button and note the reading
very high reading in one direction and low reading in the other direction indicates that diode is OK Two high readings or two low readings indicate that diode is damaged