1997 Johnsoon Evinrude "EU" 50 thru 70 3-Cylinder Service Manual, P/N 507266, Page 256Get 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 32Separate the ignition charge coil connector(s)Crank engine in short bursts until battery voltage is less than 12.5 voltsCheck battery voltage with key in the OFF position
INote Disconnect engine battery cables before proceeding with
this check3Connect to 40 amp ammeter in series between the rectifierregulator red lead and the battery side of the starter solenoid4Reconnect the engine's battery cablesReconnect the ignition charge coil connector(s)INotel The rectifierregulator requires battery voltage on the purple lead to operateBefore proceeding, verify battery voltage at terminal strip purple leads when key is ON