What I learned yesterday

[John McLaughlin]

The other day I lost power in my starboard engine. So I limped back to dock on one engine. so I did the usual check and still no power. As the saying goes dead as a door nail. The manual said in power check the fuses. So I took the cap off and tried to pull the fuses with just my fingers no luck. Something made me look inside the cap and low and behold there was the white thingamigg. My brain went into gear and I realized it was to pull the fuse. So I pulled all the fuses to include the spare ones (at the time I did not realize they were spares) Anyway they all looked good to me but still the same result no power to the engine. So it was time to call in the mechanic. Of course the first thing he did was pulled the same fuses I had and yup one was bad. He replaced it with the corresponding spare and off we go. I told him I did the same thing but did not see a blown fuse. He was very nice and said he had younger eyes oh and he also told me the second bank were spares. As I said learn something knew everyday

 

[Scottintexas]

But what made the fuse blow??

My daughter mistakenly hooked battery cables up backwards for a moment that blew them,

 

[biglar155]

Make sure you replenish that spare. I carry spares for every fuse on the boat.

@Scottintexas Sure. Daughter. I see. Under the bus she goes.

(I once blew my main fuses hooking the battery up backwards as well. After checking the color and polarity twice. Sigh. I'm not normally that un-handy. I was having a REAL off day. )

 

[John McLaughlin]

I need to follow up. Well the fuse solved the starting issue. Both engines started and ran fine for about 3 miles in the no wake mode. However near the entrance to the river I began to smell something. It was rubber the voltage regulated was smoking like a sieve. It now needs to be replaced along with the bracket. Oh well

 

[Seadeals]

The fuse generally isn’t the problem, it’s the messenger. I am interested as to which component failed. If you get a chance, post a picture of the culprit.

 

[John McLaughlin]

It appears to be the volt regulator as it was smoking like a steelmill chimney

 

[Seadeals]

Just to confirm (lingo differences) part 20 in the diagram?

 

[buckbuck]

I would be doing some homework to determine why the regulator failed. Was something preventing it from dissipating heat? What is the output from the stator?
Just seems unusual for it to breakdown.

 

[tdonoughue]

I agree. But that said, it is more likely the regulator failed than that the fuse failed. Fuses almost never fail. A regulator I heard of failing. Once.

Keep us posted!

 

[Beachbummer]

I have heard of regulators going bad. It's many times what goes bad in alternators in cars too, and I think of those as somewhat disposable like bulbs. Any electrical components that gets really hot during operation tends to be at higher risk for failure in my experience

 

[ZGhost]

To be sure you find the root cause, follow the “5 why?” rule. Why did the fuse fail? Why did the regulator fail? Why did ..... fail?
you will eventually find the problem source. If it is something other the regulator, you might burn the new one? Something to think about.

 

[tdonoughue]

@Beachbummer , I agree in general. But on these Yamaha boats I think it is relatively rare. But you are exactly right as to alternators.

 

[WREKS]

Googling "What causes voltage regulators to fail?" indicates that good ground connections are very important.