Fuel Gauge Help!

[KJ]

I need help determining what is going wrong with the fuel gauge on my boat. With the system off, the gauge goes down to below E and when running it stays pegged above F. Once in a while I will see it bounce down from F to what I think the level actually is, but it is not the same each "bounce". It will go from F to 3/4 to nearly 1/2 and then back to F and stay there for some time.

Any ideas would be great!

 

[studlymandingo]

Re: Fuel Gauge Help!

Most likely it is a shorted wire. Take the leads loose from the sending unit then turn on the key. If no change it is either wiring or the fault of the gauge. At that point, you can remove the "s" wire from the gauge, if no change still, replace the gauge, if it drops to "e" time to run new wires.

 

[Solittle]

Re: Fuel Gauge Help!

It could also be the sending unit itsef - a common problem and easy to replace.

 

[KJ]

Re: Fuel Gauge Help!

Thanks for your help, I will give this a try.

 

[Texasmark]

Re: Fuel Gauge Help!

Don't know your electronic moxy.

Battery voltage goes thru ignition ON switch to fuel gauge system.

Gauge and sending unit are in series with battery voltage. Sending unit resistance changes from a small resistance (35 ohms roughly) to a large resistance ( 265 ohms for a number; probably pretty close for a guess). One of those numbers is supposed to record E on the Fuel gauge and the other F; don't remember which.....doesn't matter.

With the fuel tank float bouncing up and down all the time it wears through the "sending" part of the system and the circuit opens up....just like the fuel system sending unit does on your truck if you live on a piece of .......rual road like I do....BTDT

Once the circuit is open, the gauge either pegs F or E; don't remeber which and it doesn't matter; it's one or the other.

Hopefully you get the idea.

Mark

 

[BLU LUNCH]

Re: Fuel Gauge Help!

I've posted this before I have installed one of these Livorsi fuel senders in my Wellcraft, It has a 60 gallon 33 inch deep tank, You want to talk fuel gauge swing on a 1/2 empty tank in 2-3 footers. After installing one of these there is NO needle float what so ever. They are pricey but worth every penny.....http://www.livorsi.com/catalog/waterproof.htm http://www.livorsi.com/pdf/GSFLC2-GSWLC2.pdf

 

[puddle jumper]

Re: Fuel Gauge Help!

My boat had the same problem i found that the plug on the back of the fuil gauge was loose .An easy way to test this is to un plug your fuil sending unit and it will read eather full or emty.If it reads emty tuch the two wires together and it should read over full.Then with the gage reading over full wiggle the wires all the way up to the gage and if it does not move the problem is probably
the sending unit is worn out.

 

[Tail_Gunner]

Re: Fuel Gauge Help!

This can be a very simple solution, just take a $10.00 ohm meter and measure the resistance you sending unit display's.

That is pull it out of your tank, hook a ohm meter, move the flotation device up and down, if the ohm meter varies widly you have a bad sending unit.

They are a very inexpensive device and usually they are the culprit, before you go to any great lenghts be sure of the integerity of your sending unit............8)

 

[DUKE1]

Re: Fuel Gauge Help!

Here's another idea. I got tired of replacing the sending units so I went with manual gauges. Granted I can't get the reading on my dash, but I just pop my round access hatch over each tank and I have the gauge to read. For me anyway...two less things to break or be replaced any time soon (I hope). You just need to know the depth of your tank then you can get the manual gauge. They are cheaper too. For clarification the manual fits into your tank the same as the electric unit.
Duke1

 

[ricksrster]

Re: Fuel Gauge Help!

My boat did the same. What was happening was that the send wire connector on the back of the gauge was grounding out making the gauge always read full when the key was on. With the key off, the gauge should go to just below empty.

 

[KJ]

Re: Fuel Gauge Help!

Thanks everyone for your help! Looks like it was definitely the sending unit.