1990 Johnson Evinrude "ES" Cross V 88 thru 115, 150 thru 175, P/N 507874, Page 296Get this manual
Cranking Discharge Method 1Check battery voltage e If voltage is greater than 12.5 volts, go to step 2
e 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
this check
engine battery cables before proceeding with
3 Connect to 40 amp ammeter in series between the rectifier
regulator red lead and the battery side of the startef solenoid4Reconnect the engine's battery cablesReconnect the ignition charge coil connector(s)The rectifierregulator requires battery voltage on the purpie lead to operateBefore proceeding, verify battery voltage at terminal strip purple leads when key is ON
5Start the engine and run at approximately 4500 rpmThe engine's ammeter should indicate nearly full output6, 9, or 35 ampsAs you continue to run at 4500 rpm, the voltage should stabilize at approximately 14.5 volts and the alternator output should begin to decreaseelf the engine's ammeter doesn't indicate the above, check stator condition before replacing rectifierregulatorTachometer Circuit