1997 Johnson/Evinrude EU 25, 35 HP 3-Cylinder outboards Service Manual, Page 241Get this manual
RectifierRegulator Tests Variable Load Tests To test the operation of the rectifierregulator, you must be able to run the engine continuously at approximately 4500 RPM, such as in test tank or on marine dynamometerThe test consists of monitoring the system's response to partially discharged batteryTwo methods for performing this test are described belowVariable Load High Rate Discharge Method INotel 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 the key is ONReconnect the purple lead bullet connector
1Disconnect battery cables
2Connect 0-40 amp ammeter in series between the rectifierregulator red lead and the battery side of the starter solenoid
3Reconnect the engine's battery cables