Help! Lost engine power while underway

[SaltyDogGloucester]

Hello, went out for a nice trip today until the engine died on our way home while still underway. Had to drop anchor and wait to be towed back to our mooring.

It was very odd because our batteries are all reading good and wiring appears to be in tact. Kill switch was fine. The engine is not turning over at all, no light no sound whatsoever. Must be electrical but where do I even start?

Thank you in advance for any suggestions!

 

[Specialk]

What year and model of engine

 

[SaltyDogGloucester]

What year and model of engine

It’s a Yanmar 2011. Model: 4BY2

 

[Specialk]

It sounds like it could be the main engine relay found inside of the main electrical box on the left side of the engine. the relay was blue and inside the black electrical box. Any BMW dealer should have it. I had the main relay go out on mine and the engine and panel was just dead. It’s a cheap part and worth a try.

 

[Specialk]

The main power relay is the one on the far right. Amazon has them.
BMW multi purpose relay. 4 prong. Sky blue 29.94

 

[SaltyDogGloucester]

Thank you very much! Definitely worth a try and see if that is it.

 

[SaltyDogGloucester]

Good news and bad news. My husband found a loose fuse and popped it back into place. That gave us engine power back, however, now we have a constant alarm beeping from the Yanmar display panel. It says, “Main throttle sec throttle.” The red light stays on when you turn the key and beeps constantly.

Any ideas? We ran the engine for a bit and tried moving the throttle but it didn’t clear the alarms or beeping. It seems awfully coincidental that the fuse had popped loose and now we have this alarm but maybe totally unrelated? Feels like one step forward two steps back.

Thank you in advance for any help or guidance you can provide.

 

[Brian John]

What size fuse is this? Fuse clips should have enough tension to prevent the fuse from popping out. I would check the fuse for proper seating and that the connections of the fuse clips are holding the fuse properly. I am assuming this is not a bolt-in fuse.