1998 Johnson Evinrude "EC" 90, 100C, 105C, 115, 150, 150C, 175 60 deg. LV Service Manual, P/N 520210, Page 296Get this manual
Cranking Discharge Method
1Check battery voltage If voltage is greater than 12.5 volts, go to Step If voltage is less than 12.5 volts, go to Step 32Twist the spark plug leads and remove them from the spark plugsCrank the engine in short bursts until battery voltage is less than 12.5 voltsCheck battery voltage with key OFF3Disconnect the battery cables4Connect 0-40 amp ammeter in series between the rectifier regulator red lead and the battery side of the starter solenoid5Reconnect the battery cables and the spark plug leads
INote The
rectifierregulator requires battery voltage from the purple lead to operateBefore proceeding, separate the rectifier regulator purple lead bullet connectorVerify battery voltage at the engine harness connector when key is ONReconnect the purple lead bullet connector6Start the engine and run it at approximately 4500 RPMThe ammeter should indicate nearly full output20 or 35 ampsWhile continuing to run at 4500 RPM, the voltage should stabilize at about 14.5 volts and the alternator output should begin to decrease If your results vary, check the stator's condition before replacing the rectifierregulator