1975 Evinrude 40 HP Outboards Service Manual, PN 5093, Page 82Get this manual
Set Ohmmeter Scale to Hi Ohms Connect the ohmmeter's red lead to groundSee Figure 7-18Ohmmeter should show open circuit (infinity)If ohmmeter shows any reading, stator is shorting to ground OHMMETER LEADS MUST BE REVERSED FOR EACH TEST OR PRESS POLARITY BUTTON aRepeat above test using yellow rectifier leadReading on one check and no reading (infinity) on the other checkdiode is good; both readings high, diode is (open) defective; both readings zero, diode is (shorted) defectivebRepeat above test using yellow blue stripe leadReading on one check and no reading (infinity) on the other checkdiode is good; both readings high, diode is (open) defective; both readings zero, diode is (shorted) defective2Repeat test procedure with ohmmeter between red lead of rectifier and yellow gray stripe lead of rectifierReading on one check and no reading (infinity) on the other checkdiode is good; both readings high, diode is (open) defectiveboth readings zero, diode is (shorted) defectiveaRepeat test between red and yellow lead of rectifierReading on one check and no reading (infinity) on the other checkdiode is good; both readings high, diode is (open) defective; both readings zero, diode is (shorted) defectivebRepeat test between red and yelloW blue stripe lead of rectifierReading on one check and no reading (infinity) on the other checkdiode is good; both readings high, diode is (open) defective; both readings zero, diode is (shorted) defective