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#1
posted to rec.boats
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green ground wire
I bought a 1996 sea ray f-16 jet boat last summer and the seller said
the engine had recently been rebuilt. I noticed that the fuel gauge did not work when I bought the boat so this week I decided to replace both the fuel level sender in the tank and the fuel gauge. The new fuel gauge still does not work. In trying to figure out why the gauge does not work, I noticed the fuel tank had a green wire attached to it and the other end of the green wire was connected to the engine block at the same point where the battery +12 volt line is connected to the input of the starter solenoid. Because of this, the fuel tank is always +12 volts. I verified this with a volt meter that the tank is +12 Volts. This is apparently why the fuel sender is not working since their is no ground for the sensor. My question is this. Should I disconnect the green wire from the input to starter solenoid where the +12 V line is attached, and connect the green wire to where the battery negative black wire is connected on the engine block? I'm assuming that when the engine was put back into the boat someone connected the green wire in the wrong place. The boat worked fine all summer so the tank at +12 volts did not cause any problems other than the fuel gauge malfunction. Thanks for your help. |
#2
posted to rec.boats
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green ground wire
"bobk123" wrote in message ups.com... I bought a 1996 sea ray f-16 jet boat last summer and the seller said the engine had recently been rebuilt. I noticed that the fuel gauge did not work when I bought the boat so this week I decided to replace both the fuel level sender in the tank and the fuel gauge. The new fuel gauge still does not work. In trying to figure out why the gauge does not work, I noticed the fuel tank had a green wire attached to it and the other end of the green wire was connected to the engine block at the same point where the battery +12 volt line is connected to the input of the starter solenoid. Because of this, the fuel tank is always +12 volts. I verified this with a volt meter that the tank is +12 Volts. This is apparently why the fuel sender is not working since their is no ground for the sensor. My question is this. Should I disconnect the green wire from the input to starter solenoid where the +12 V line is attached, and connect the green wire to where the battery negative black wire is connected on the engine block? I'm assuming that when the engine was put back into the boat someone connected the green wire in the wrong place. The boat worked fine all summer so the tank at +12 volts did not cause any problems other than the fuel gauge malfunction. Thanks for your help. Yes. |
#3
posted to rec.boats
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green ground wire
All major components on a boat should be electrically bonded
together. This is especially important to human safety. Your gas tank is electrically floating? Then it is a situtatoin similar to what destroyed a 707 over Elkton MD. That is dangerous. Gas tank should be grounded using a 10 AWG (or heavier) ground wire so that engine, tank, and all other major metal components are bonded electrically and so that bonding makes a connection to water. A discussion of this concept: http://www.thomson.ece.ufl.edu/lightning/ Summary http://www.thomson.ece.ufl.edu/lightning/IEEE.pdf IEEE paper http://www.thomson.ece.ufl.edu/lightning/video.html Video Apparently that gas gauge problem is but a symptom of a more dangerous and serioius problem. bobk123 wrote: I bought a 1996 sea ray f-16 jet boat last summer and the seller said the engine had recently been rebuilt. I noticed that the fuel gauge did not work when I bought the boat so this week I decided to replace both the fuel level sender in the tank and the fuel gauge. The new fuel gauge still does not work. In trying to figure out why the gauge does not work, I noticed the fuel tank had a green wire attached to it and the other end of the green wire was connected to the engine block at the same point where the battery +12 volt line is connected to the input of the starter solenoid. Because of this, the fuel tank is always +12 volts. I verified this with a volt meter that the tank is +12 Volts. This is apparently why the fuel sender is not working since their is no ground for the sensor. My question is this. Should I disconnect the green wire from the input to starter solenoid where the +12 V line is attached, and connect the green wire to where the battery negative black wire is connected on the engine block? I'm assuming that when the engine was put back into the boat someone connected the green wire in the wrong place. The boat worked fine all summer so the tank at +12 volts did not cause any problems other than the fuel gauge malfunction. Thanks for your help. |
#4
posted to rec.boats
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green ground wire
"w_tom" wrote in message ups.com... All major components on a boat should be electrically bonded together. This is especially important to human safety. Your gas tank is electrically floating? Then it is a situtatoin similar to what destroyed a 707 over Elkton MD. That is dangerous. Gas tank should be grounded using a 10 AWG (or heavier) ground wire so that engine, tank, and all other major metal components are bonded electrically and so that bonding makes a connection to water. A discussion of this concept: http://www.thomson.ece.ufl.edu/lightning/ Summary http://www.thomson.ece.ufl.edu/lightning/IEEE.pdf IEEE paper http://www.thomson.ece.ufl.edu/lightning/video.html Video Apparently there are some exceptions to what is bonded and what is not. My boat is equipped with Volvo diesels and Volvo purposely does not bond the engine, shaft and props to the boat's common bonding system. The reason is to reduce electrolysis due to DC leakage. I found this out when the boat was modified with thrusters. The installer connected the thruster housings and motors to dedicated batteries that where also connected to the main batteries for charging. He also connected the thruster motors to the bonding system. It was discovered during regular in-water hull cleaning by the diver who noticed "tingling" when he touched the shafts or props. Disconnecting shore power plus a host of other experiments did not get rid of the tingle, which was very mild, BTW ... he could feel it if he brushed a shaft or prop with the back of his hand. A call to Volvo provided the explanation of why the engines and shafts were not bonded. I disconnected the thruster batteries from the mains and the "tingling" went away. Ended up installing a separate, dedicated charging system for the thruster batteries. All bronze thru fittings, etc. are bonded. Interestingly, the electronics (radar, etc.) is obviously grounded to the batteries via the DC power return, but they are *not* bonded. So, on my boat, red is 12vdc positive, black is 12vdc negative and green is bond. Eisboch |
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