Re: Evinrude Question
The horn is turned on by completing a ground through the tan wire. The purple wire provides power to the horn so it will sound when the tan wire is grounded through the temp sensor, VRO/OMS pump, or oil tank level sensor. Any of the above components could fail and cause the horn to sound all the time. Also the horn can fail and sound all the time (with the key switch on) or if the tan wire shorts to ground in the harness. To verify that the horn is good, split the control box, remove the tan wire from the horn, turn on the key switch. If the horn sounds, it is bad. If it does not, reconnect the tan wire and disconnect each of the above componets until the horn stops, if the horn stops,then you know which componet failed and turned the horn on. If the horn still does not stop, the wiring harness must be at fault.