New fuel gauge not working correctly, any ideas?

[winston]

I had a new fuel gauge fitted but it reads incorrectly. When the ignition is turned off it reads 1/4 and when the ignition is on it reads full regardless of how much fuel is used, Foe example I used 30 L from the 60 L tank but it still reads full (or past full). Any ideas? Thanks Winston.

[ozynorts]

Re: New fuel gauge not working correctly, any ideas?

Sounds like someone got the wiring wrong. Can you pull it out and check or get the people who installed it to fix it?

[Back In Black]

Re: New fuel gauge not working correctly, any ideas?

Ask Moejoes.....

He's the fuel expert

[Fed]

Re: New fuel gauge not working correctly, any ideas?

Disconnect the sender wire from the S terminal on the back off the gauge and see what it reads when the ign is turned on.

[winston]

Re: New fuel gauge not working correctly, any ideas?

Fed, with the sender wire detached and power turned on, the needle moved below empty and stayed there. Cheers Winston.

[Fed]

Re: New fuel gauge not working correctly, any ideas?

Then you have a short circuit to ground on the sender wire or at the sender itself.

[seashawgal]

Re: New fuel gauge not working correctly, any ideas?

My fuel gauge was working perfectly until I fixed it ha ha. Typical, I pulled the floor panel up and cleaned off the terminals and reconnected them. Then the gauge just read empty all the time despite the fuel level. So then I go around to fixing it again and I cleaned the terminals once again and the gauge read full. Great I thought until I'd used most of the fuel in the boat and it still read full! You can't connect the two wires on the under floor fuel tank wrong because the terminals are two different sizes. Help me what do you think is going wrong? Nothing is ever easy or straight forward is it.

[Flex]

Re: New fuel gauge not working correctly, any ideas?

Checked the wires to you lugs at fuel gauge aren't corroded?
If your 100% sure the connections are on the right terminals it has to be a dodgy connection.
That or the fuel gauge is faulty.
Grab multimeter and check continuity of your cables to the lugs


Sent from my iPhone using Ausfish forums

[seashawgal]

Re: New fuel gauge not working correctly, any ideas?

Thanks for that info I just googled what a lug is learn something every day with the combined knowledge on this forum

[winston]

Re: New fuel gauge not working correctly, any ideas?

Some success. I found that the guy that installed the fuel gauge had managed to create a short circuit. When he attached the sender wire, the little star washer on the nut cut into the ground wire as it was too close. Thanks for the wiring diagram Fed. The only issue now is that it is inaccurate, i.e. 30L (in a 60 L tank) reads 3/4 and 40L reads full.

[docaster]

Re: New fuel gauge not working correctly, any ideas?

Possibly the wrong sender then. What sort is it? Pull it out and slide the float up and down to simmulate level

[clarky180]

Re: New fuel gauge not working correctly, any ideas?

Make sure your sender unit matches the ohms on the gauge, they must be compatable or it wont read correctly. Usually they are 0 to 190 ohms or 230 to 33 ohms both gauge and sender must be the same.

[winston]

Re: New fuel gauge not working correctly, any ideas?

Cheers, I will check. Thanks Winston.

[Fed]

Re: New fuel gauge not working correctly, any ideas?

Don't bother checking, you already have the correct sender (a wrong sender would read in reverse).

It's a calibration thing, you need to adjust the sender float.

My advice is to live with it because you will never get it accurate for all situations as the level at the sender varies with the level of the boat.
Get to "Know Your Tank" is the best solution.

My boat goes for 20 Kilometers before the needle comes off 'Full' but at 1/8th of a tank I'm really on 'Empty'.

[Chimo]

Re: New fuel gauge not working correctly, any ideas?

If you can do it there is a lot to be said for a length of dowel with graduated markings that you just insert into the tank and note the height of the "wet" section.

After a while you will probably get to know that "x" hrs running burns "Y" liters of fuel.

Until you have a good handle on hrs run equals a known fuel burn why don't you just add a 10 liter fuel can or two to your safety gear.

Gauges in boats tend to be indicative at best and given the impact that a change in sea state can have on consumption just carry a reserve in case. If you dump your reserve into the tank after each trip you will get a good idea of how much you used and when you refill the reserve you will always have fresh non E10 fuel at hand.

KISS is best.

Cheers
Chimo