Electrical System Overload

steinwmj

New Member
Jun 26, 2009
15
Simi Valley, CA
I have a 240SD. Was out on the lake and loss power (similar to turnng off the run switch). Batteries switch is turned to off position and the Power Trim still works. All gages are frozen and there is no electrical to the rest of the boat when battery switch is turned to on position. Pushed "Reset" button but power is not restored. Any ideas where to start looking.
 
Bad fuse or fusible link. They're mounted to the battery cable terminal on the starter. Fuse is a block mounted to the terminal with a wire connected to it. Fusible links are wires attached to the battery terminal and crimp connected to the wiring harness. You need a voltmeter to test the fuses. Fusible links can be tested by pulling on them. If one feel rubbery and stretches then it's bad. The wire burned out leaving just the insulation. Links are color coded for current capacity, get one the same color when replacing
 
Thanks, I will check it out. Got to figure how to get down to the starter (not much room). Would a bad or low battery cause this problem while the engine is running? Also while checking fuses, noticed that the fuse box is very loose, so thinking that maybe this cause an short or something - just a guess.
 
If the battery was dead, then the power trim would not work. Check the battery voltage, but the trim pump draws a lot of current. I doubt that that would work and nothing else.
 
Both batteries at 12V. Power trim works on either battery, and when the battery switch is turned to the off position. Not sure what the best way to get to the fuse on the starter is. Do you know if this is something that has to go to the dealer?
 
Pretty trivial. Depends on what you are comfortable doing.
 
Did you check the breaker back by the battery? When tripped, a little black arm swings out. I know that if it trips it will cut power to the dash, but not sure if it affects trim pump.
 
There is no battery breaker on the 240SD.I checked as many fuses as I could except the 90amp fuse at the starter. I'm not sure how to get to it - there seems to be no room or I will have to lay on top of the engine and hang down to the starter but I am not sure if that is best to do. I am sure a tech knows how to do it easily.
 
It's not a 240SD thing - things change from year to year. I was just taking a guess that you had a newer 240SD as I didn't see the year listed in your original post. I don't recall when SR started using this breaker, but are you positive? It would definitely be somewhere under that port-side seat where the batteries are. It could be mounted on the floor or the hull side. Looks something like this: http://bluesea.com/category/3/10/productline/overview/150

I think you pretty much got it figured out how to get to your starter - there's really no trick involved. Any way you can get to it will work.
 
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Thanks for the suggestion though. I looked again and there is nothing like this on the boat. I will take a try at it myself, but also call the dealer on Monday to see what's involved with them doing it. Thanks
 
I changed the 90 Amp Fuse, connected batteries and when I turned the switch to one of the batteries I heard a pop down by the starter/fuse and I have no power to the instrument panel. Any ideas what could be happening? Maybe bad batteries?

Mike
 
Problem resolved. It was the orange wire from the 90amp fuse to the alternator. It rubbed against a bolt wearing down the insulation. I was surprised that only about 1/3 of the actual wire was left. Had to splice-in a marine grade (water proof) butt connector and wrap with conveluted tubing. Installed new fuse and all electronics back. Found out that there was a Mecury Marine Service Bulletin issued. Thanks to all who helped.:smt038
 
Glad you got it figured out! :smt038

Hopefully you're having better weather out there than we are.
 
Weather is great in So Ca. Haven't had the boat out in a few weeks, so this week taking some time off to enjoy the sunshine with the family.
 
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Almost 11 years later I am faced with same scenario - 90A fuse blown that is mounted to the starter. I have no idea how one might get to it without removing a number of components.

I am very impressed that the younger you managed to change that out!
@steinemj
 

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