1999 228 Seafarer 225 sw ox 66 Yamaha blowing 40 amp fuse

[ibuyre111]

just purchased a used grady and it has been blowing the resetable 40 amp fuse that runs thru the perko switch.
It knockes out all my electronics and power thru my switch panel(running lights, Bilge etc). Also my engine shuts down. My mechanic seems to think that this power line is feeding power to my electric fuel pump. The enging still cranks but wont turn over.
any ideas?
thanks
Tom

 

[seasick]

It is possible that the breaker is bad but to see if it is motor related, keep the ignition off and all breakers rockers, radio gps etc off. Turn on the battery switch and the 40a breaker should stay set.
Now start to turn on accessories one at a time, turn on breakers one at a time and turn on rockers on at a time, each time checking the 40a breaker. If one device pops the breaker, tuen everything off, reset the 40a and then turn on that specific device. If the breaker pops that device or wiring to it is probably the issue. If it isn't one specific device that pops it but the sum of several devices, the 40a breaker is probably bad.
Note that we haven't turned on the motor yet.

Now turn off everything, breakers, rockers and turn on the ignition but don't try to start the motor. If the 50A pops, it is motor related. If it doesn't pop, it isn't the fuel pump since that turns on when the ignition is on.
It gets trickier from there. A common cause is a worn wire that is shorting out.
let us know what happens.

 

[seabob4]

This is rather interesting in that typically an engine's electrical system and the boat's electrical system are completely independent of each other except for a common ground.

 

[seasick]

This is rather interesting in that typically an engine's electrical system and the boat's electrical system are completely independent of each other except for a common ground.

I am not sure what you are saying but usually the main breaker powers everything except the bilge pumps. By everything, I include the ignition feed but not of course the started feed. The ignition feed runs through the same rigging harnesses as other devices and must be fused. The main breaker is the fuse.
So if the started were to lock up, the 40 a main wouldn't see it but if the ignition switch were to short to ground, the breaker would pop.

 

[seabob4]

Seasick,
Mercury, Suzuki, Honda, all are circuit protected by fuses on the powerhead. The engines electrical is NOT connected to the ships system on the positive side, only through the grounding side. There is no hot lead coming out of the engine harness that runs through the 40A breaker protecting the ships systems...

 

[BobP]

Motors have nothing to do with Ship's aux power feed, righfully so as you have experienced.

Ships main power feeder to be on breaker, not fuse.

Motors have their own protection.

Get that fixed.

 

[seasick]

Seasick,
Mercury, Suzuki, Honda, all are circuit protected by fuses on the powerhead. The engines electrical is NOT connected to the ships system on the positive side, only through the grounding side. There is no hot lead coming out of the engine harness that runs through the 40A breaker protecting the ships systems...

I guess I see what you mean, by not connected to the ship's electrical system: you mean not connected to the load side of the breaker/distribution panel. I know the motor has fuses but I though the ignition signal was powered off of the aux feed.
If that is the case, that makes trouble shooting easier since a motor issue wouldn't pop the 40A main.

 

[ibuyre111]

40 amp fuse popping

Thanks for the reply everyone. Its in the hands of my mechanic now. He spent about an hr looking at it today and wants me to pull the boat, bring it to his shop. This boat was rewired recently and he feels that there in lies the problem. He couldnt remove screws on the large plastic cover at the back of the engine. Frozen tight. He feels that there, inside might be the problem.
I'll keep you posted

 

[seabob4]

Seasick,
Mercury, Suzuki, Honda, all are circuit protected by fuses on the powerhead. The engines electrical is NOT connected to the ships system on the positive side, only through the grounding side. There is no hot lead coming out of the engine harness that runs through the 40A breaker protecting the ships systems...

I guess I see what you mean, by not connected to the ship's electrical system: you mean not connected to the load side of the breaker/distribution panel. I know the motor has fuses but I though the ignition signal was powered off of the aux feed.
If that is the case, that makes trouble shooting easier since a motor issue wouldn't pop the 40A main.

And visa versa, an electrical issue (and it would have to be a big one) in the ship's electrical issue will not cause problems on the motor side...

 

[ibuyre111]

Re: 1999 228 Seafarer 225 sw ox 66 Yamaha blowing 40 amp fus

Thanks everyone for the responses concering my electrical issue.
My mechanic went over the whoile boat and is still givinng me heck for not using him to survey the boat before I bought it.
It seems that whoever wired the boat(it was rewired) totally screwed up the the whole boat. I was told he should be shot!!
I have the boat all up and running great. My mechanic was all over the boat and basically seperated everything the way it should have been in the first place.
Loving my first season with my Grady 228...some boat!!
Tom