Probably Polarity


I need your assistance with my boat wiring.

I have changed trolling motor batteries in my boat and since, I have burned 2 twist plugs. My cables aren’t marked so is it possible I may have crossed them or is that something that would cause my dilemma.

What could be causing me to burn the plug? It has a 4 wire Marinco outlet.

Thank you


On a 12/24 marine electrical system, wiring the batteries is critical. Use a meter (not a test light) to determine if the polarity is correct and the battery cables are correctly connected.

The circuit protection in the positive leads at the battery should trip before you burn up the plug. If you don’t have fuses or breakers at the battery, now is a great time to add them.


Has Power. Won’t Start.


I have a 2004 Premier pontoon boat that will not start.

Premier Pontoon Boat

I have battery power as the motor will raise and lower, the radio will come on, etc.; however, the engine will not crank.

It worked well prior to putting it away for the winter.

What can I trouble shoot? Is there a fuse? How can I tell if the ignition switch is bad? Is there a neutral switch that can go bad? When I turn the key, nothing happens. BTW, I have a 50 horse Four Stroke Mercury.

Thanks in advance for any advice.


First check the in-line fuse on the engine near the starter solenoid (follow the battery cable into the engine from the battery to the starter solenoid). If the fuse is good, check for power at the key on the red or red/green wire.

This will solve your problem,



Hi Kevin,

I have an older Misty Harbor that I need your help with.

The boat battery and boat battery wiring is good. Up until three days ago, the motor would trim without any problem. Now there is no power to the motor or power tilt and trim. I seem to have power, because the navigation lights still work fine.
ANL fuse for boat wiring

Any ideas?



There is a small, inline fuse near the starter solenoid on most outboard engines. It sounds like you may have accidentally blown this fuse.

The lights are working because the are usually powered through a different circuit.

Hope this helps,


Suspect Stereo


Last fall, I purchased a 2005 Playbuoy Pontoon boat with a factory equipped electric motor. The only thing that didn’t work at time of purchase is the tilt control for the outboard motor – at least that I knew of.Playbuoy Pontoon Boat

Ever since the purchase, I have not been able to keep a charge in the boat batteries. A couple of weeks ago, I purchased a new battery charger after measuring that I was not getting charging voltage to two of the four batteries. While wiring in the new charger, I observed arcing to the negative battery post on one of the two batteries serviced by the new charger, obviously indicative of some sort of electrical load, although the primary key switch was in the off position…all accessories off…etc.

I was able to charge the batteries to the point that both chargers shut off, and next time on the water, suddenly lost all electrical power to the electric outboard motor after only about thirty minutes of cruising time.

In consideration of the tilt control not working, and the wire arcing, is there a connection? Or might there be a short circuit that is a known problem for this model?



Hi Doyle,

I would use the process of elimination to find your excessive draw.

  • Buy an inexpensive meter that can measure DC current.
  • Install the meter in-line with the battery connection that is causing the arc and observe the current.
  • If everything is truly off, there should be no draw.
  • If there is a draw, try disconnecting devices at the fuse panel until the draw goes away.

My best guess is that the stereo is not powering down completely and the internal amplifier is drawing your battery down.

Good luck,


Mystery Part Identified

Dear Kevin,

I just bought a used pontoon boat and it has a battery switch connecting two 12v batteries. There are three studs on the switch and connected to the bottom stud is a device consisting of a metal strip with a small box and another stud connected to two red cables that supply the power to the boat.

The connection is corroded and I would like to replace it, but I don’t know the name of the electronic part. I think it must be some kind of fuse or protector.In line breaker

Sorry I can’t be more specific, but I haven’t been able to find a name for this part.

Hope you can tell me what this part is.



Hi Larry,

The rusty device is an inline circuit breaker. You can buy a new one from our sister site.

Hope this helps,



Thanks so much for the info. We greatly appreciate your kind help.

Keep up the good work.