1998 Johnson Evinrude EC 5 thru 15 HP Four Stroke Service Manual, Page 321Get this manual
DRC6802
DRC6803
Rectifier Ohmmeter Tests9.9 (211cc)
INote Disconnect battery cables before proceeding with this checkIT] IT]
1Disconnect all rectifier leads from engine wiring harness2Calibrate ohmmeter on appropriate scaleConnect one lead to clean engine groundConnect the other lead to the rectifier yellowblue leadNote the readingReverse the ohmmeter connections or press the "reverse polarity" button and note the reading high reading in one direction and low reading in the other direction indicates the diode is OK Two high readings or two low readings indicate the diode is damaged