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Help! Battery Cables Swapped. Need Troubleshooting Advice.

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Hey Guys,

It was one of those days. Dead battery, time to replace, previous owner had 2 starting batteries so I replaced the dead battery with a deep cycle. In the process I had to swap the batteries so the new deep cycle was on position two (house battery) in the process I done goofed... bad. Embarrassed to say it but I spun the starting battery around and ended up switching the terminals polarity and I didn't double check. When I switched on the battery switch I let the magic smoke out. Switch started smoking and became physically difficult to turn, internal melting I'm sure, it was on for about 5 seconds and shut right off and disconnected.  So first step was to replace the battery switch and I have since done that.

After the switch replacement everything that isn't ignition controlled works just fine. Tested (Bilge, horn, trim, lights, fresh water pump, engine cowl motor, etc) all working properly.

If I attempt to start it nothing happens, its silent. The captains call solenoids also don't work but I believe they will not actuate unless there is ignition power which I do not have. There is no power to the ignition switch. I also crawled under the helm and looked at the ignition breaker. It was not popped however there was NO power to the breaker, I spot checked the other breakers and all read 12v. 

I checked the 40AMP mega fuse by the battery switch and it had 12v on each side.

I do not have a light in my BER branded VSR and I am not sure if that is relevant or not, just an observation.

 

I am sure hoping there is an inline fuse or something that I blew and can't seem to locate somewhere that kept me from trashing all the expensive stuff, computer, alternator, coils, etc.

Any insight on such a fuse or tips for continued troubleshooting would be GREATLY Appreciated.

 

Thanks,

Michael

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Had the same thing this year and it was the 90 amp fuse at the starting post. Also the Fuse at the back of radio needed to be replaced.

 

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Would like the 2 of you to post the cost of repairing fuses.  Might give others a guide line. 

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Thanks @ColdOne. I got one of those ordered, they do look like a joy to replace, considering their location but if that's it is, I will be THRILLED. I'm slightly concerned that I don't have any power to the ignition switch and ignition breaker at the helm, I'm not sure that the 90 AMP fuse on the starter is responsible for that but 1. I haven't been able to track down the wiring diagram yet, and 2. Merc did specifically put that fuse there to protect in the event of a battery cable mix-up (according to research) so I am going to try it and keep everyone posted. 

 

@cyclops2 So far my total for the mix-up is $35 for the 90 AMP fuse and $65 for a new dual battery switch. (Labor done myself)

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Check the circuit breaker on the engine.  Or if you have a Battery Isolator

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I am willing to place a side bet that only fuses are shot.  I know you feel like crap....many have done this.  I did it on a car once.  Smoked the battery.  Fortunately that’s all it was.

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Thanks guys for all of the help and kind words in my time of stupidity. Fortunately, I can now follow up and bring this one to a close. The final piece was indeed the 90 AMP fuse that bolts to the hot post on the starter and separates it and the power that runs to the alternator, etc. I swapped that out and was in good shape.  Apparently Merc introduced it specifically for that reason. 

Total for my mess-up was $93 ($65 for the new battery switch and $28 for the 90 amp fuse at the local marine store).  I'm consider myself lucky but I suppose by 2007 they realized people do dumb things sometimes and build in protections. 

Here are a couple pics of the fuse, it was a bit of a pain to get to, on my boat under the motor, in the back, on the starboard side. (Just follow the hot wire running to the motor). Other than location it was straight forward.

Thanks,

Michael

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Safety Note: Be sure to DISCONNECT all the Negative Battery Cables from all Batteries whenever you are working on the electrical system. Especially when changing the 90 amp fuse at the positive connection of the starter solenoid. We don't need another blown fuse or worse!

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I always put all the batteries negative cables to the centerline of the hull.  That helps prevent accidents by people multi tasking. I keep the same polarity in as straight a line as possible............ I also spray red paint at the + positive battery terminal and the cable end.

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