Need to ground a fuel tank

[Jimsalv]

I am in the process of installing a new fuel tank. The original tank was only bonded to the aux tank, with neither being grounded. So now the question is, where should I ground the tank, I don't want to connect to the battery ground.

Thank you to anyone who knows.

 

[Halfhitch]

The battery is exactly where you want to ground it. Don't pick up a ground at a location that is in a daisy chain of connections. If you want a good steady dependable fuel gauge reading, use a dedicated wire directly to the battery.

 

[Hookup1]

Usually there is a green wire to the tank ground and to the fuel fill. Not sure where goes but it does go into the harness. I just hooked them up! Check GW Owners Manual for your boat (available online at GW).

 

[Jimsalv]

The battery is exactly where you want to ground it. Don't pick up a ground at a location that is in a daisy chain of connections. If you want a good steady dependable fuel gauge reading, use a dedicated wire directly to the battery.

Ok, that being said, there is 1 red wire for the sending unit, is that correct or is something missing.

 

[Hookup1]

From my GW manual...
Fuel tanks sender Main / Aux. Pink and Pink/White
Also a white wire. Both connected to sending unit.
Fuel Grounds. Green goes into harness as well - attached to tank.


This was good enough for GW. Don't run new wires. Make sure terminals are good. If not cut them off and clean wire with Dremel wire brush, dielectric grease and new crimp connectors. The red and white pair at sending unit runs straight to fuel display/fuel fills - eliminating problems with the green running all over the boat.

Boat grounding can be a confusing subject. Some Manufacturers wire the greens to the zinc system that is bonded together. Battery negative (black or yellow) may not connected to it.

Color codes on my boat are buried inside the split duct but there are two wire connectors on the boat and the sending unit. Not sure if the "green" in in there.

 

[SkunkBoat]

The battery is exactly where you want to ground it. Don't pick up a ground at a location that is in a daisy chain of connections. If you want a good steady dependable fuel gauge reading, use a dedicated wire directly to the battery.

Ideally it should green wire, not black. directlty from tank to neg battery. no confusion.
There should be green wire or greenw/yellow stripe from fuel fills already going to the battery.

The difference between Black and Green wire is its purpose. Black wire is a "negative return". It carries current for a circuit. Green wire indicates it is a "bonding wire". It does not normally carry current for a circuit.
This is regarding DC circuits on a boat.

 

[DennisG01]

Ok, that being said, there is 1 red wire for the sending unit, is that correct or is something missing.

It's actually "pink", but I'm only mentioning that so you have reference of the proper colors.

If your gauge works, then the tank or sending unit is already grounded.

 

[SkunkBoat]

If you're sending unit doesn't have a ground direct to battery then you can have strange problems reading. The more things you have turned on, the more your gauges are wrong.

 

[DennisG01]

Oh... what everyone is saying about a solid ground is correct - but that could ALSO be to a grounding bus bar where the bus bar is connected to a battery. That is actually a very common way that many good manufacturers do it -- and, in many ways, nicer as it keeps the battery posts cleaner with less wires on them... making disconnecting/connecting batteries easier.

 

[Ekea]

why dont you want to ground to the battery?

 

[Hookup1]

Why hack the wiring? Just clean up what is there. The are two wires to the each of the sending units - a pink and a green. The green has a green splice that goes to the tank. Green goes to "fuel ground" near the batteries. Look at Skunkboat's schematic. On my boat GW used a 2-pin trailer connector. to connect the sending unit to the harness. One side on the sending unit and the other connected to the harness. Handy if you need to disconnect the sending unit to take it out. You can see the splice in the aux tank/lower part of photo. # fuel grounds can be seen in second photo.



Unless someone hacked this up before you I would put it back together and try it.

 

[DennisG01]

Just a side note (although most comments still apply)... I'm pretty sure Jim has the older style sender that has a single pink wire going to the sender and then the sender is grounded either via the screws and a tab somewhere on the tank that has a black (or green) wire attached to it... or would have a ground wire to the plate of the sender.

 

[Hookup1]

Just a side note (although most comments still apply)... I'm pretty sure Jim has the older style sender that has a single pink wire going to the sender and then the sender is grounded either via the screws and a tab somewhere on the tank that has a black (or green) wire attached to it... or would have a ground wire to the plate of the sender.

I have seen that style of sender somewhere before. Something like this? Has a tab for the ground.

 

[Fishtales]

From my GW manual...
Fuel tanks sender Main / Aux. Pink and Pink/White
Also a white wire. Both connected to sending unit.
Fuel Grounds. Green goes into harness as well - attached to tank.

View attachment 33505
This was good enough for GW. Don't run new wires. Make sure terminals are good. If not cut them off and clean wire with Dremel wire brush, dielectric grease and new crimp connectors. The red and white pair at sending unit runs straight to fuel display/fuel fills - eliminating problems with the green running all over the boat.

Boat grounding can be a confusing subject. Some Manufacturers wire the greens to the zinc system that is bonded together. Battery negative (black or yellow) may not connected to it.

Color codes on my boat are buried inside the split duct but there are two wire connectors on the boat and the sending unit. Not sure if the "green" in in there.

Humm "Good enough for GW".... Wiring isn't their strength for sure. I wouldn't stop with their method.

 

[Jimsalv]

I really appreciate ALL the input! You all have valuable advice. Just to clarify, this is a 1992 Explorer, with an aux tank. Someone has been in there well before me. This is my 3rd season with this "work in progress" . The old tank wasn't grounded to anything, nor did the sending unit work. I have newer (08) gauges, so I went by gallons used to know what was in there. Now , the new tank is in place (not foamed!) and I now plan on grounding to a ground plate (battery ). Yes, I only have a pink wire , which I will connect to the new sending unit, and extend the tank ground to sensor ground. That should do it!

Thanks again!

 

[Hookup1]

Nothing worse than trying to understand a previous owners hack job! I'm fortunate with my 1997 GW 268 Islander. 10 years old when I bought it. All original wiring intact and working when I got the boat. Very few holes drilled in it as well. I stripped both electronic boxes and rewired the new equipment.

 

[DennisG01]

Granted the wiring may be rotten away, but look around your aux tank area - if THAT was the tank that carried the main grounding wire, then it may still be hanging around in there.

 

[DennisG01]

I have seen that style of sender somewhere before. Something like this? Has a tab for the ground.

View attachment 33514

Correct - that style has been around for eons (and is still used). It may or may not physically have a ground tab on it.

 

[Jimsalv]

Granted the wiring may be rotten away, but look around your aux tank area - if THAT was the tank that carried the main grounding wire, then it may still be hanging around in there.

No, no petrified wires!

 

[SkunkBoat]

The other problem you will find is that some new sender units (KUS) have a PINK ground wire and Black signal wire. You have to reverse them and connect their pink to your Green...

Sometimes its White and Black and Black is the signal.... That happens with LED light fixtures too.... READ THE INSTRUCTIONS.....


Regarding the Grady setup on my 265. It is pictured in the earlier post. This is not technically "bonding". It is only connecting the fuel fill and tanks to ensure they are always at the same potential. ...shit, well I guess technically that IS bonding...just not bonding ALL metal thru hulls...
You see they went back to the battery with all three green wires. However, they seem to be using the green wire as the return for the gauge.
However, the Yamaha and now my Suzuki gauge were also grounded to the the neg terminal block under the dash.

At one point early in my ownership, I accidentally dropped the three green wires out of site and was running for a day without them, Thats when crazy stuff happens. The gauges work sort of but get worse as you turn things on because the gauges are only using the connection to the Neg bus on the fuse panel under the dash. That was back with the Yamahas and I had a dash switch to view tanks separately

We ended up getting to working by jumping some 10 awg from tank to tank to Neg Battery. Later we found the three green wires laying down deep in the hole....