yahama 50 hp 2 cycle

[jack1943]

yahama 50 hp 2 cycle, 2004. warning horn will not sound after grounding the two wires on the overheat sensing unit. horn test ok. im getting power to the horn thru the yellow wire, applying an alternate ground to the horn and it sounds.
any suggestions, there is no power coming out of the cdi going to the overheat sensor, should there be.

 

[boscoe99]

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[boscoe99]

The CDI is looking for a ground from either of the thermoswitches. Telling the CDI that the switches have closed due to an excessive temperature.

The warning horn is powered via the yellow wire from the key switch being on. The warning horn is grounded to make the buzzer sound.

Have you jumpered the orange wire to the orange/green stripe wire to see if the alarm sounds? Same with applying a ground in the thermoswitch pink wire in the main engine harness?

 

[99yam40]

The CDI is looking for a ground from either of the thermoswitches. Telling the CDI that the switches have closed due to an excessive temperature.

The warning horn is powered via the yellow wire from the key switch being on. The warning horn is grounded to make the buzzer sound.

Have you jumpered the orange wire to the orange/green stripe wire to see if the alarm sounds? Same with applying a ground in the thermoswitch pink wire in the main engine harness?

If that 50 is like my 40, one temp switch tells the CDI the motor has warmed up after a cold start and the other tells the CDI the motor is overheated.
need to make sure you are grounding the proper one

 

[boscoe99]

Thanks. I forgot what the other thermoswitch was for. Getting old. Failing memory.

 

[boscoe99]

I retract my comment about the thermoswitch looking for a ground. If it is, it must be a ground internal to the CDI box.

 

[boscoe99]

Maybe this will help. Might need to trace the pink wire in the ten pin harness back to the engine harness to see to where it leads.