3YM30 Panel Chirping - Help on Passage!

[Aleainc]

Hello all we are in the middle of a seven day passage and our Yanmar panel is chirping intermittently. The alarm just quickly chirps and all the lights blink on briefly and then off. it may happen a couple times in a few minutes or not for an hour. Ideas? Thanks!

[Aleainc]

To clarify it’s a 3YM30AE.

[JPA Cate]

First thing to do is see if you have a loose wire to the alarms.

If you are close enough to shore for a mobile phone signal, see if you can download the manual for the engine, and let someone else be on watch and you study the manual. Take hard copy notes, carefully.

An intermittent like that could be a dirty connection of a wire, but also a loose one. They should feel snug, not wobbly.

[OldManMirage]

Water in the key switch. Or in your case salt water. I just had something similar happen to my Yanmar panel after a big rain. I'm assuming this is happening when the engine is not even running ? That's what mine did.

[Aleainc]

So the panel started to blink/alarm constantly, and now just turns off completely, no rpm, no hour display. You can turn it back on and it will start to blink/alarm, then shut off after about an hour or more. We have checked connections as best as possible and didn’t find any chaffing or loose connections. Seems to get worse as the engine runs for longer. Totally stumped.

[JPA Cate]

Can you figure out a way to bypass the computer to start and shut down the engine?

If not, I'd go back and have the shop work it out. I am not a good electrician and not an
an electronicker at all.

Ann

[OldGreyB]

Often boat or car electrical issues are due to poor grounding, but as each of the Yammer sensor devices and associated idiot lights have their individual grounds, it would appear your issue may be a common mode supply side problem.

As you state all the lamps and the buzzer are involved, then it probably is a common mode failure. The symptoms you describe could be a high resistance joint within the wiring circuit that is live when the engine is running. As time goes on, the high resistance causes heating, which in turn causes a higher resistance, until the current can no longer pass, and the unit turns off.

My trouble shooting is based on the attached wiring diagram of the control panel from the Yanmar 3YM30 service manual. If this is not what you have then I need to know what panel you have.

Question: Does the engine stop switch always work, even when the panel appears dead?

If yes:
A) The most obvious place to start is when the engine is first running, check with your multimeter for greater than 13.7V , or using an incandescent light on two wires (not an LED) for voltage between a known good boat electrical ground (BLACK wire or Stud) and terminal 30 [RED] wire , then terminal AC [RED]. Confirm you have good steady voltage at both terminals.

B) Next with the engine still running, check with your multimeter for greater than 13.7V , or using an incandescent light on two wires (not an LED) for voltage between a known good boat electrical ground (BLACK wire or Stud) and terminal + on the Tachometer / hour meter. Confirm you have good steady voltage voltage greater than 13.7V at the + terminal.

C) If you have a multimeter, and are not seeing the same voltage at terminal 30 [RED] and the terminal + on the Tachometer, pull the 3Amp fuse downstream of the Key switch and check the contacts and spray with electrical contact cleaner. Replace the fuse.

D) Recheck the voltages at terminal 30 and Tachometer + terminal, they should be the same , greater than 13.7V.


If sometimes or not sure:
1) When the engine is first running, check with your multimeter for greater than 13.7V , or using an incandescent light on two wires (not an LED) for voltage between a known good boat electrical ground (BLACK wire or Stud) and terminal 30 [RED] wire , then terminal AC [RED]. Confirm you have good steady voltage at both terminals.

• If not a steady voltage at terminal 30 [RED] when the engine is running. Stop the engine and pull the multi connectors on the harness and sprayed with electrical contact cleaner (not WD 40)? . Then reseated the connectors. Restart the engine, check again for steady voltage at terminal 30 [RED].

2) Assuming you have steady voltage at terminal 30:
When the unit starts beeping and flashing, check again, for voltage between a good boat electrical ground and terminal 30 [RED] wire , then terminal AC [RED]. You may find that terminal 30 [RED] is a solid voltage greater than 13.7V and terminal AC [RED] is intermittent, indication that the key switch contacts are problematic. The use of an incandescent light on two wires is entirely suitable for this test as it provides a resistant load itself, and will flash, whereas depending on the quality of the multimeter you are using, you may see a suitable digital voltage swings or not.

3) When the unit is apparently dead, check again, for voltage between a good boat electrical ground and terminal 30 [RED] wire , then terminal AC [RED]. If no voltage on terminal AC [RED]. then you have confirmed the switch is defiantly faultily.

4) If the switch is showing as faulty, then you can use a wire with alligator clips on each end and bridge between 30 [RED] wire and terminal AC [RED] and wait and see if that cures the problem while the engine is running. Do remember to remove this temporary jumper once you have confirmed or not the switch is the issue.

Do the above tests and report back on what you found on A thru D and 1 thru 4.

[Aleainc]

Thank you so much for all the helpful info! I am going to try and tackle this tomorrow and will let you know what happens.

[Aleainc]

Pictures of panel back attached!

[OldGreyB]

Via PM, the OP provided the following information:

1) The red feeds at the Yanmar panel connections have 13.8 Volts
2) OP can stop the engine with the stop button
3) The warning lights come on before OP goes for the start
4) A "Click" , no start and low voltage (7.7V) at terminal 30 [RED] when going for an engine start. This is an indication its probably not the Yanmar panel, but boats internal upstream wiring.

Use the attached diagram and test points to find where the voltage first goes from 13.8V to 7.7V. This location or the termination before it will be the likely culprit. Look for loose connections, loose connector, corrosion.

[Danm1]

Mine was recently chirping intermittently. Topped off the oil and it stopped.

[Aleainc]

Traced the problem back to the circuit between the starter and the engine battery since I was occasionally reading 0 volts from the starter. Started pulling off cables to check for continuity and the lug off the end of the battery to starter cable just popped off! Like it was never crimped . Crimped on a new end and all seems to be ok. Thank for all the assistance!