Yanmar Heat warning light

[mchaple]

Hello,

Yanmar 3GM30F Heat warning light and buzzer stop working when I open up the swith. Every thing else OK.

Can I use a multimeter to check the heat sender unit, if so what values I should expect, to start some where.

Regards,

Mike

[never monday]

I think you are asking..

when you function the test switch the overheat light and buzzer don't sound.
Is this correct?

[GordMay]

Goto: cruisersforum.com/forums/f14/basic-engine-gauge-theory-testing-645.html
http://www.cruisersforum.com/forums/...sting-645.html

[mchaple]

Thanks all for your response.

I will read basic-engine-gauge-theory-testing-645 and try it out in my boat next week.

Will let you know how it goes.

Regards

Mike

[mchaple]

Hello guys,

I replaced the heat sender unit in YANMAR 3GM30F and:


- Measured voltage from cable to engine block - reads 13 volts
- Measured ohms from sender unit to engine block - reads 500 ohms.
- Open switch light is off buzzer is off, is this the way it should work?

The only light that came on when I open the switch is the charging light, when I started the engine light goes off.

In the instrument panel there is a toggle switch that when I activated it the oil light came on and buzzer sounds.

Is all of this OK?

Regards
Mike

[bill good]

I think the test would be no ohms reading ie O/C for the switch it closes when the temp rises above normal. The 13v reading is normal & if you short the connection at the sensor to the motor the alarm will operate. You can test the old one by heating it up in water to prove it faulty & then testing if it closes with the multimeter. I think both temp & oil lights come on with the test switch but would have to check myself next time I am on my boat.

Regards Bill

[mchaple]

Hi Bill,

Thank you for your comments. I think I will end up replacing the panel, it look like the buzzer is short circuit. When I remove the bulb light for the oil pressure the buzzer goes off high pitch. When I remove the bulb light for the temperature buzzer goes off low pitch.

Regards,

Mike