1994 Johnson/Evinrude "ER" 9.9 thru 30 outboards Service Manual, Page 130Get this manual
Function TestsS.L.OWThe 20 thru 30 HP ignition system incorporates the 5.L.DW TM warning system, which gradually limits engine speed to approximately 2000 RPM when engine temperature exceeds 1800 (82 C)To resume normal operation after the 5.L.0WTM warning system has been activated, the engine must cool to 1550 (68 C) and the engine must be slowed to an idleThe 5.L.0WTM warning system depends on input from the temperature switch tan leadOn remote electric start models, the 5.L.0W TM warning system is isolated from other warning horn signals by blocking diode in the engine wiring harnessTemperature Switch 1Disconnect temperature switch tan lead2Install correct test propellerStart engine in test tank and run at 3500 RPM3Attach engine harness tan lead to clean engine ground If engine slows to approximately 2000 RPM, test temperature switchRefer to Temperature Switch Test, Section If engine does not slow to approximately 2000 RPM, check wiring or replace ignition moduleRefer to Ignition Plate ServicingBlocking DiodeRemote Electric Models If the 5.L.0WTM warning system is activated when the key switch is turned to the ON position, test engine harness blocking diode1Disconnect engine harness red connector2Disconnect temperature switch tan leadf1l3Calibrate ohmmeter on scalebetween engine harness tan lead and engine harness tan pin Note reading4Reverse meter connections or press "polarity" buttonNote reading very high reading00in one direction and low reading in the other direction indicates diode is good5Replace engine harness blocking diode if your test results vary6Complete all circuits disconnected during this testDR2344