Yanmar 3GM30FC (1996) - alarm not working

[roman]

Hi,
recently I noticed that alarm buzzer on instrument panel is not working when I turn the key
switch on and before I push the start button to crank the engine. The engine is starting without
any issues immediately, however not hearing the sound of alarm is worrying as I don't know
if it will also not work as a warning for legitimate reasons (e.g. oil pressure alarm). I
visually inspected wiring harness and couldn't see anything that would be obviously wrong.
I would appreciate any opinions/suggestions how to troubleshoot the issue. Instrument
panel on the boat is large B-type. Thank you in advance.

 

[Benny17441]

You must have a toggle switch to test the temperature alarm. If you activate it with the engine running the light in the panel should turn on and the buzzer should sound. If the buzzer does not sound then it would be safe to assume it will not sound in a real fault situation. If the panel lights are operating properly (Alt and Oil Pressure with key switch on and engine off and Temp when toggled with engine running) then the buzzer is likely at fault and would need replacement. (Do check the connectors for the buzzer). I gather you have a Yanmar engine with Panel "B". Yanmar utlized two types of buzzers, one with two leads and a multi leads one. The most common for the "B" panel is the multi lead unit. The part # for the "B" panel is 104271-91352 and it lists for $184.40. Check the part number for your specific year model and engine as they could vary. The part is quite expensive but much cheaper than a ruined engine. Some have substituted and adapted industrial buzzers or Jet ski buzzers with various degrees of results. Good luck.

 

[roman]

You must have a toggle switch to test the temperature alarm. If you activate it with the engine running the light in the panel should turn on and the buzzer should sound. If the buzzer does not sound then it would be safe to assume it will not sound in a real fault situation. If the panel lights are operating properly (Alt and Oil Pressure with key switch on and engine off and Temp when toggled with engine running) then the buzzer is likely at fault and would need replacement. (Do check the connectors for the buzzer). I gather you have a Yanmar engine with Panel "B". Yanmar utlized two types of buzzers, one with two leads and a multi leads one. The most common for the "B" panel is the multi lead unit. The part # for the "B" panel is 104271-91352 and it lists for $184.40. Check the part number for your specific year model and engine as they could vary. The part is quite expensive but much cheaper than a ruined engine. Some have substituted and adapted industrial buzzers or Jet ski buzzers with various degrees of results. Good luck.

Thank you very much for quick response and good suggestions to start with Benny17441.

 

[kloudie1]

Roman, on the back of the buzzer, the red and black wire is the power to the buzzer.. If the starter push button is working that red/black wire should have 12V on the buzzer end.. At the buzzer again, the yellow and white wire goes to the oil pressure switch. The buzzer end should show a ground when the engine is not running. if that wire is not showing ground or continuity with ground, the OP switch or a connection between the buzzer and the switch is bad. If that yellow/white shows ground, then the buzzer is probably bad. You can test the buzzer by putting a short jumper between the yellow/white at the buzzer and ground (a bigger black wire, or engine block) With 12V at the red/black, the buzzer should sound.. While you are there, after that test, ground the white/blue (temperature switch) to see if that makes the buzzer sound.. Some folks, put off by the high price of the Yanmar buzzer, have installed two separate buzzers from a parts place, like Radio Shack to replace .
http://www.radioshack.com/product/index.jsp?productId=2062399

 

[Calif. Ted]

The part # for the "B" panel is 104271-91352 and it lists for $184.40.

Ouch !
I recently replaced the alarm on a 2002 Cat320 with that engine, the tech guy was unable to confirm it was correct at the time I ordered but for $24 I rolled the dice. There are some pics and other info that may be helpful at the website I'll attach.
http://www.catalinadirect.com/index.cfm?fuseaction=product.display&product_ID=2384

 

[robertsapp]

When we bought our boat, our buzzer didn't alarm on low oil pressure, which is the one you hear when you start the engine. I removed it, applied 12 volts to each alarm input (there are four total) and discovered that the only one that didn't work was the low oil pressure - all the other inputs worked fine. I bought a pin extractor tool at Radio Shack for about $6, and swapped the pins in the wiring harness so that the oil pressure signal now goes to a good alarm input (you only need three unless you have a saildrive). Problem solved. Might be worth checking on yours. The oil pressure input gets cycled the most, so it makes sense that it might die before the other three inputs.

 

[roman]

Roman, on the back of the buzzer, the red and black wire is the power to the buzzer.. If the starter push button is working that red/black wire should have 12V on the buzzer end.. At the buzzer again, the yellow and white wire goes to the oil pressure switch. The buzzer end should show a ground when the engine is not running. if that wire is not showing ground or continuity with ground, the OP switch or a connection between the buzzer and the switch is bad. If that yellow/white shows ground, then the buzzer is probably bad. You can test the buzzer by putting a short jumper between the yellow/white at the buzzer and ground (a bigger black wire, or engine block) With 12V at the red/black, the buzzer should sound.. While you are there, after that test, ground the white/blue (temperature switch) to see if that makes the buzzer sound.. Some folks, put off by the high price of the Yanmar buzzer, have installed two separate buzzers from a parts place, like Radio Shack to replace .
http://www.radioshack.com/product/index.jsp?productId=2062399

Hi Claude,
thank you for responding. I did try what you suggested. With the key switch turned on,
the yellow/white wire at the buzzer was showing ~12V. Does this imply that the
alarm buzzer is bad? Few other observations, when key switch is turned on and engine not
running
1) I can test the buzzer by toggling a switch, to test the temperature alarm, and this one
is working and making alarm to sound
2) The oil-pressure warning light is also not working - only charge lamp is turned on

I am very new with this and so I have more questions than answers, but can possibly
be that, the oil-pressure sensor is actually bad, and alarm buzzer is working, because
the test 1) makes it to sound ?

Thank you for any suggestions. Roman

 

[scorpio77]

Hi Roman, from a different perspective, my buzzer was not sounding for the oil press, I found that the oil sensor at the front of the engine has two cables, the rear one goes to the press indicator and the front one goes to the buzzer, in my case, this last one was broken, so I only attach the cable again to the front of the sensor and it worked again.
I know you may already checked this cables, but these are my 2 cents.

Jose Salgado
ODay 322 1987
DREAM ON