Fuel Gauge Showing Full

[Skinnyrib]

2006 Zodiac Medline.

Fuel gauge showing permanently full although tank is empty.

I have fitted a new gauge (ASAP Supplies - excellent) with European resistance - the old one was a bit tired.

Any ideas ? - I suppose this now points towards the sender unit - any tips/suggestions on what I should do now greatly appreciated ......and how I can get at the sender unit ?

Thanks

[Last Tango]

Meter the sender unit with a DMM. Be very, very careful. Remember, your "empty tank" is full of petrol vapour and if 12 volts finds it's way directly onto that sender it could be very bad indeed. Make ABSOLUTELY sure the new gauge is compatible and wired up properly.

[paddlers]

If you can get to it remove the sender unit from the tank and test it manually. These things are notoriously unreliable and inaccurate on boats anyway !

[TonyC]

You bought a gauge with a European resistence, but are you sure the sender is European?

When i changed our fuel gauge on our XS RIB, I had the same issue, turns out is was a US sender on the fuel tank.

Had to leave the wong one in for a week while waiting for the correct one to arrive - it was quite funny watching my staff get confused.

[Skinnyrib]

Thanks for your replies lads !

Last Tango - for making me extra careful when testing.
Paddlers - removed and it worked fine
TonyC - spot on ! looks like the sender is US so a new gauge en route from ASAP Supplies

Thanks