1998 Johnson Evinrude "EC" 90, 100C, 105C, 115, 150, 150C, 175 60 deg. LV Service Manual, P/N 520210, Page 294Get 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
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 the key is ONReconnect the purple lead bullet connector1Disconnect 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
4Following the manufacturer's directions, connect the variable load tester (carbon pile) across the battery terminalsStevens Model NoLB-85 and Snap-on Model NoMT540D are examples of testers availableExcessive battery discharge rates might overheat battery causing electrolyte gassingThis might create an explosive atmosphere5Start the engine and run it at approximately 4500 RPMUse the variable load tester to draw the battery down at rate equivalent to the stator's full output The ammeter should indicate nearly full output20 or 35 amps