Fuel Gauge Help

[odieman150]

Hi all i have been experiencing problems with my fuel gauge for awhile now and have just got the nod from the minister to get it fixed . I have discovered that the sender seems to be the issue (youtube) but part of my problem is that the sender is seized in the fuel tank so some sort of collateral damage will occur upon removal. I have looked at installing a stand alone fuel flow meter instead of replacing the sensor so hopefully avoid any damage to the fuel tank. My question (if anyone is still reading that is) does anyone have any experience with any of the meters under $100? Thanks in advance guys.

[Fed]

How did you test (youtube) the tank sender?

[552Evo]

Good question, I'll be following this thread. My boat doesn't even have any fuel gauge and my builder says that fuel senders are notoriously inaccurate so it's not worth the effort of installing one. Really I guess I just want to know when I've hit a reserve amount I suppose so I know to limit travels until a refill.
It's easy to eyeball the level just by lifting the floor hatch on my boat. But I can only see half the height of the fuel tank.
My boat was supplied with a "vessel view" screen system so there may be other options for fuel usage or levels as well.


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[scottar]

What engine?

[odieman150]

Hi Fed here is one of the youtube vids i used to check the problems. https://www.youtube.com/watch?v=yU1BDBZWl8A https://www.youtube.com/watch?v=HJkuEH2aqMU https://www.youtube.com/watch?v=Zm8E-_yNSK8 there were quit a few others as well.

[odieman150]

What engine?

115 Optimax 2006 Scottar

[Fed]

The video was as much help as a dying duck in a thunderstorm mate.
Aside from no sound & having to try & speed read the sub titles of a deranged mind I gave up when the poster made the rookie mistake of saying 'test for current' when he should have said 'test for voltage'.

Try this...

1) In a nutshell make sure you have 12 Volts to the gauge (Terminals I & G) when the key is turned ON.

2) Remove the sender wire from the S terminal & the gauge should peg to EMPTY.

3) Then use a small piece of wire & short between the S terminal & GROUND terminal & the gauge should peg to FULL.

Senders are pretty robust & more often than not the problem is either in the gauge or the wiring.

[odieman150]

thanks Fed i will try that asap

[odieman150]

The video was as much help as a dying duck in a thunderstorm mate.
Aside from no sound & having to try & speed read the sub titles of a deranged mind I gave up when the poster made the rookie mistake of saying 'test for current' when he should have said 'test for voltage'.

Try this...

1) In a nutshell make sure you have 12 Volts to the gauge (Terminals I & G) when the key is turned ON.

2) Remove the sender wire from the S terminal & the gauge should peg to EMPTY.

3) Then use a small piece of wire & short between the S terminal & GROUND terminal & the gauge should peg to FULL.

Senders are pretty robust & more often than not the problem is either in the gauge or the wiring.

Thanks again Fed for the info. I ran through the process late this arvo and came up with the same outcome that the gauge is fine and checked wiring through to sender. All good. Still looks like the sender with the ohms not changing with different fuel levels so looks like some surgery to replace it.

[scottar]

If it is looking like a major, might be worth investigating a smartcraft gauge (possibly even second hand) if your model engine is compatible. I do not know for sure but they may have either a fuel used reading that is reset-able or a programmable tank capacity that counts down using information straight off the emm without the need for a tank sender

[Fed]

That doesn't sound good odieman, to be 100% sure you could carry out the same tests right at the sender terminals and if the gauge pegs both ways from there then the sender is done.

I'm not a huge fan of measuring the 'fuel level' by keeping track of what goes in Vs what goes out.

A working level sensor will tell you exactly what the level is so long as you allow for it's forward/aft location & the angle of the boat, it doesn't get any easier than that.

[gofishin]

...I'm not a huge fan of measuring the 'fuel level' by keeping track of what goes in Vs what goes out...

Keeps working for me Fed.

Just did my annual tank drain (well for another reason too this time), and the tank had ~1 - 2L more in it than ‘the bible’, and this in ~640 odd litres put thru it from memory.

Ok yes, so this 1 -2 L also depends on the 20L nikko marks in the jerry’s, and hence if they have gone a bit out of shape since new (when I marked them), and also depends on how many old fuel top-ups I did from these after the last drain (can’t remember, don’t have my book with me now) – but even if it was a few L’s more or less, accuracy is still under 1% error. Cross-reference to my 10-bar gauge on the tank (also checked for calibration occasionally) … plenty good enough for me.


Some fuel sensors i have come across over the years are terrible for accuracy, but some are quite good as you say. Regardless, the more fuel measurement 'systems' you can rely on the better i reckon.

[Toygut]

Hey mate, this may be a log shot, but IF you are within range of a Boating and RV franchise, I remember seeing their fuel gauges (not indicators, these mob are claiming they are gauges!) that allow significant swell and trim influences but the needle will always give you the average. They were adjustable depending on tank depth and were compatible with some sounder displays ( I can't remember what brand). But what I do remember is that they were $90! Either way, they still came with an illuminated display, but I do apologise I cannot remember the brand. Boating and RV used to be Biased Boating. I hope this helps!

[odieman150]

Thanks so much Toygut but i have replaced the sending unit and am back to hoping the reading is close. (always carry an xtra 20lt in case)