2006 Johnson SD 30 HP 4 Stroke Outboards Service Manual, PN 5006592, Page 80Get this manual
ENGINE CONTROL CAUTION SYSTEMS If the engine speed is over 3000 RPM, the overrevolution caution control will be activatedThe engine speed will be automatically controlled by ignition interruption and lowered to approximately 3000 RPM To cancel the overheat caution control, the cylinder wall temperature must be reduced to less than 158F (70C) and, at the same time, the engine speed must be decreased to 1500 RPM or lower
Checking the Caution Lamp
Remove the blueyellow lead wire from the oil pressure switchStart the engineTouch the blueyellow lead wire to the engine body groundIf the caution lamp comes on, the oil pressure switch circuit and the caution lamp circuit are functioning normallyIf the caution lamp does not come ondisconnect the caution lamp lead wires from the engine harnessConnect pin test cord, PIN 5034617, then connect the caution lamp lead wires to 1.5V batteryIf the caution lamp does not come on, replace the lampCaution Lamp Test Battery connection Positive (+) Pink Negative (-) Black Result