Fuel Gauge Help

[fimpel]

I understand how to hook up a fuel gauge from reading the forums.
But I have a couple questions.
The sending unit on my tank has 2 ground wires, The diagram I seen in the forums shows only one ground wire and that goes to your battery.

So I only need one ground?
The ground on my gauge comes from the ground on other gauges just like the positive?

Also I have one fuel gauge and 2 tanks.
I have a switch for L/R tanks.
So I run my sender wire to the switch and then from switch to sender hookup on gauge?

 

[JoeCrow]

Re: Fuel Gauge Help

Not sure what type of boat you have,
I have an 86 Bayliner and it has 2 grounds as well
One goes to the negative on the battery,
the other goes to a grounding rail that runs to the front of the boat for all the rest of the grounds

 

[fimpel]

Re: Fuel Gauge Help

I have a '85 Ranger 350v.

Heres the diagram I was talking about.

 

[Silvertip]

Re: Fuel Gauge Help

Yes you need two grounds. The gauge needs a ground to work and so does the sender. Ground is ground. It doesn't matter whether you connect both to the negative terminal of the battery or to the ground terminal on another gauge, or to the ground buss on the fuse panel. Electrically, they are all the same point and end up at the negative terminal of the battery. The only reason a ground buss is used in the first place is so that you don't need to run the ground wire from each accessory all the way back to the battery which would be a terrible waste of wire. When you see a ground symbol like the one on the gauge in the diagram, electrically that means the same thing as the ground wire between the sender and negative terminal on the battery. A ground symbol is used in schematics and wiring diagrams because it eliminates the need for lots of lines which clutter the diagram. It simply doesn't matter where you ground that wire.

As for your L-R switch (should have three terminals), the sender terminal from each tank is connected to the N.O. (normally open) contacts on the switch. The center (common) terminal connects to the "S" terminal on the gauge.

 

[fimpel]

Re: Fuel Gauge Help

Thanks for the help. silvertip is this what you mean by the switch?

 

[Silvertip]

Re: Fuel Gauge Help

Yes - almost. The center terminal is not a "gauge sender" -- that terminal connects to the "S" terminal on the gauge.

 

[fimpel]

Re: Fuel Gauge Help

Thats what I meant, but I guess I said it wrong.
Thanks for your help.