Fuel gauge repair

[MeanJeanne]

My fuel gauge goes to full as soon as i flip it on. Any ideas? Ground wire? If so where is it on a 28TE with a Yanmar?
Thanks!

[johngus]

if it goes to full either the wire is shorted of the sender is shorted.disconnect at the sender and see if it shows empty with disconnected.then with the wires connected should read full.
you can test the sensor with an ohm meter as well.with moving the float the resistance should change

[Norseman]

Engine box model?
If so you may have to remove a large piece of the aft deck to gain access to the fuel sender.
My fuel gauge is way off but using a much more accurate fuel used computer instead: FloScan.

[Wfmdfm]

I had an issue with my gauge reading 3/4 all the time. Checked out the wiring and no issues found. I made the determination that the sender was bad. Pulled the aft deck and removed the unit. Purchased a replacement from Centrion in Florida. Easy to work with on the phone. The unit just arrived this weekend $75 plus shipping. It is a capacitance unit not a float. Good to lift the aft deck. I can tidy up and clan a few things, put new sealant on it and hope to not be in there for awhile.

Update.. the unit is in and now reads 5/8 of a tank. Seems close. I feel the swap was successful but wait a tank or two for the victory dance. Having the deck up was a good chance to fix a few drains and also the fuel tank vent.