An Odd Blowing Of The Ignition Fuse on 4.3l...Help please...

[newfiez]

I’m having the same issue as what was mentioned in an archived topic titled Blown Ignition Fuse - 2006 Sea Ray 4.3 Litre S/N 0W635564 on a 4.3 too, except it blows the fuse while accelerating to get the boat on plane. Doesn’t blow the fuse any other time. I checked the purple wire from the coil to the computer, and the purple wire to the alternator, some chaffing but nothing appears to be through. I separated all the wires so they’re not touching each other or the engine, still does it. Could it possibly be a bad coil?

 

[alldodge]

First what is your serial number, and assuming this is a 4.3 Merc sterndrive, but your sig list 115 Rude?

What size is the fuse?

 

[newfiez]

Sorry, I was going with the thread.

Its a 2005 4.3 Alpha One Gen 2. S/N 0W043891. There’s a 20a fuse in there, and that keeps blowing. I put a 30a in there to see, and it popped right away when it happened.

 

[achris]

.... I checked the purple wire from the coil to the computer, ...

You have a 'TKS carburetor-ed ' engine (based on that serial number), so no computer.

That 20A ignition fuse supplies power to EVERYTHING on the engine and instruments. It could be something like the tacho, or an engine part. I would start isolating things, and put an ammeter in place of the fuse to see just how much current it's pulling (and to save having to replace fuses all the time, which gets expensive.

Chris.........

 

[alldodge]

Blowing a 30 amp fuse and nothing else changes tells me this is a dead short. It only happens when throttling up, look at the shift plate and carb linkage, thinking a frayed wire

 

[newfiez]

I checked all around the shift plate, and linkage area, there’s nothing I can see that could come in contact with it. I would suspect it would happen while shifting into gear also, but only while trying to get the boat on plane. I could sit on the dock in neutral and rev it up the same way, with nothing blowing. I’ll get an ammeter and go from there.

 

[dubs283]

look at the shift plate and carb linkage, thinking a frayed wire

also check the remote control, usually lots of wires bundled up behind the bolster where the remote is mounted. i have seen more then one wire frayed behind there