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. |
bobk123
Nov 20
2006
|
| Green is usually the color for bond except in the case of Eisboch's Volvos.
You should find thay all of the green wires are tied together at the engine,
common bonding plate, or at least to a dynoplate. Eisboch will correct me if
I'm wrong.
Jim |
Jim
Nov 21
|
| Making an assumption that this 16 foot boat spends 95% of its time
hauled out and sitting on a trailer and only 5% of its time afloat, I
don't know why a bonding system would be all that important. The risk
of electrolytical activity is only present ro any meaningful degree
when the boat is in the water, and then it's normally a *very* slow
process. Sacrificial anodes for the drive, risers, and heat exchager
should be sufficient, I would think. |
Chuck
Nov 21
|
| That's how I understand it. Eisboch |
Eisboch
Nov 21
|
| Might be important to bond the gas filler assy. Might be important to bond
the jet. Anodes are good to have but they serve a different purpose.
This would be a good topic for you to research for an article in your
boating periodical.
Jim |
Jim
Nov 21
|
| Yes, the boat is in the water only about 5% of the time. I think the
sending unit will work once I ground the fuel tank because the sending
will then have a ground instead of the +12 volts. I'll attach the
green wire to the engine block first and see if the sending unit will
work. If not then I'll rewire as you suggested. Thanks all for your
help. |
bobk123
Nov 21
|
| Yes. |
Calif
Nov 21
|
| >the engine had recently been rebuilt. I noticed that the fuel gauge |
Short
Nov 21
|
| Yes to number 2 and but not sure about number 1 question. I checked
the sender and gauge off the boat by hooking it up to just the 12 volt
battery and they worked fine. As far as the ground question, the green
wire is attached to the tank at a welded strap on the tank. Also
connected to this strap besides the green wire is a black ground wire
for the fuel sending unit. From what I read in this forum a heavy
gauge green wire is normally an earth ground wire and used for ground
when connected to shore AC power. I don't have AC on this boat just 12
V DC current so I'm not sure why a green wire is on this small 16 ft
boat. |
bobk123
Nov 21
|
| Ok, so I assume you removed the sender and checked it - good. Now
that wire run should be duplicated on your boat in exactly the same
way you tested it. The way you would do that is to ring out the wires
from the gauge to their termination points at the tank. Find the power
leads and that should be that. Greenwire is normally associated with ground in AC systems, but not DC
systems. I assume that your 16 foot boats is probably all DC and no
AC available. So my thinking on the issue is that you need to find
the black ground wire, or just rewire the gauge/sender as you tested
it and just disconnect anything you can't readily identify from the
tank. That extra wire could be a work around for some other accessory
on the boat that was removed, but it could be an active ground. I would just ground it to whatever point is closest on the engine
block. |
Short
Nov 21
|
