3 prong 12 volt plug

[islandboat]

I have an electric reel that uses a 3 prong 12 volt, 15 amp twist-lock plug for power. It is already wired up on the boat and working but I still have a question that some one may be able to shed some light on. <br />Positive wire with 30 amp fuse; 12 volt positive terminal. no problem.<br />Ground wire to batteries negative post, simple.<br />3rd wire wire, ? <br /> I think it is attached inside the reel handle as a static ground, but this is not 120 volts that would need a static ground. Factory wiring harness connects the 3rd wire to the ground terminal on the battery along with the negative wire for the reel motor. I know that it is already connected and working O.K. but why the "static" wire? Did I miss something on 12 volt boat wiring?

 

[crab bait]

Re: 3 prong 12 volt plug

the reason i use a '3-prong' plug is so it's impossiable to get polarity wrong.. <br /><br />with the 3-prong,, you can only plug in one-way..