Blown Fuse but Why

bhammer

Ensign
Joined
Mar 29, 2008
Messages
963
2006 4.3L MPI SN ow654383.

First time in a long time, weather was good to take the boat out with the family. Before hand, started the boat up and ran for about 15 minutes on muffs. Checked fluids all was good.

Got to the lake and backed on down and the boat would not even crank over, nor would the trim work. I left the blower switch on so it drained the battery. The battery was dead in a matter of 45 minutes so I knew the battery was bad. Ran to store and picked up dual purpose battery and Emory cloth to clean the terminals. Hooked it up and the engine cranked over and charging showed just shy of 14v. All looked good.

Just before the no wake zone ended, the boat died. I checked to make sure the terminals were tight and they were. The trim worked just fine as it is wired direct to the battery. Everything else was a no go, including the Mercruiser warning system. I knew it wasn't the battery. There is a 20 amp fuse that is right off the battery that runs up to the instrument cluster. That fuse was blown. The only ting I can think of, is that my daughter was using an air pump for a tube. It had been running five minutes and we have used it many times before.

I didn't have any spare 20 amp fuses and got a short tow in. I thought about jumpering it but didn't want to create more issues. Got it back on the trailer and home for troubleshooting. I have replaced the fuse and cannot get it to fail again.

Everything that the wire goes to is clean and tight. Any thought from you all? I have thought about a weak fuse but to be honest, this is the first time I have ever had a fuse blow without a problem, be it a short or too much current draw.
 

Don S

Honorary Moderator Emeritus
Joined
Aug 31, 2004
Messages
62,321
Re: Blown Fuse but Why

I've found blown fuses before, even on my own boat, car, truck, whatever and replaced them and never had another problem.
They probably act like light bulb filiments. After so long they just fail. No warning, no reason, they just fail.
 

bhammer

Ensign
Joined
Mar 29, 2008
Messages
963
Re: Blown Fuse but Why

Thanks Don. Guess I have just been lucky in the past. But hey, Now, I have a bunch of spares (different ratings) for the three different ones back at the battery. I plan on checking the current draw in the morning when I have a little more light to see what I have just to double check.
 
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