Boat takes off and the blows fuse

bajaman350

Cadet
Joined
May 12, 2006
Messages
9
I just bought a 22' scarab with a 7.4L Mercruiser MPI. The boat had fuel problems before, the electronic fuel pump filter was clogged up. I got that problem fixed, and now I have another problem, so I figured I would try this forum again because it was so helpful the first time. Anyway, the boat gets up on plain and runs for a short time and then all of a sudden, the thing just shuts down, like someone had turned the key off and won't restart, I was able to trace out that the ignition fuse was blown, so I changed it, tried it again, same thing. Put it on the trailer, hook some water up to it and it seems to run fine. I have had to be towed in 2 times in a row because of this problem. If anybody has any idea of why the fuse keeps blowing, please help me. It is a 20 amp fuse, and the fuse panel says it is supposed to be a 20 amp fuse for that switch. Any pointers would be appreciated.
 

Bondo

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Staff member
Joined
Apr 17, 2002
Messages
70,468
Re: Boat takes off and the blows fuse

I'm Not fimilar with Your motor,....<br />But,...<br />What Circuit is protected by the Fuse you're Replacing,.??...<br />There's a Dead Short in it Somewhere......<br /><br />Finding it probably Won't be Easy,.... I'd try the Shake, Wiggle,+ Pull Tests 1st......
 

baydreamer

Cadet
Joined
Oct 31, 2003
Messages
8
Re: Boat takes off and the blows fuse

My bayliner did exactly the same thing, could idle all day and when on plane, fuse would blow, found shorted wire rubbed on bolt head and bouncing around would blow fuse.
 

bajaman350

Cadet
Joined
May 12, 2006
Messages
9
Re: Boat takes off and the blows fuse

Thanks for all of the pointers, There is an hour gauge in the engine compartment, and it comes on when you turn the key on. Anyway, the connectors for that had come off and were laying up against the engine, I put new connectors, and away we went... Now boat takes off and hauls, not blows fuse, thanks for all the help!
 
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