2002/2003 Johnson SN/ST 2 Stroke 3.5, 6 8 HP Outboards Service Manual, PN 5005466, Page 70Get this manual
ELECTRICAL RECTIFIER RESISTANCE TESTS68
RECTIFIER RESISTANCE TESTS68
IMPORTANT: Disconnect battery cables before
proceeding with this check
Move ohmmeter lead from engine ground to rectifier red leadConnect the other ohmmeter lead to the yellowgray rectifier leadNote the readingReverse the ohmmeter connections or press the "reverse polarity" button and note the readingPerform the same procedure on the yellow and yellowblue rectifier leadsNote the readings 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 damagedReplace the rectifier if your test results vary