6 wire fuel sending unit - what is this?

buddy0

.
Sep 17, 2014
33
Hunter 33 Oriental, NC
Just when I thought I had fuel sending units figured out, I come across this in my 2005 Hunter 33-2. Not sure how to test it or what to replace it with.

There are 3 wires coming into the connector from the boat and 6 wires coming from the sending unit.
There are 0 ohms between two of the six wires on the unit and infinite between all other combinations with the unit removed from the tank.

The tank is almost empty. The gauge has always read full since I bought the boat. (I've probably put 3-4 hours on the engine and never put diesel in it.) The gauge reads empty with the wires disconnected.
So I'm pretty sure the sending unit is bad - but what to replace it with and which wires to connect it to?

Pics attached.
 

Attachments

buddy0

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Sep 17, 2014
33
Hunter 33 Oriental, NC
Nice find. Thanks joker460.
Didn't find that one in my searches.
 

senang

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Oct 21, 2009
221
hunter 38 Monaco
The Tank monitor system is from New Providence Marine (or the older company).
Ask for Dennis Ferriello ("dennis@feriellosales.com), he gives the best support in the marine industry.
Website "newprovidencemarine.com".
I have the same system, but only for watertank and black watertank on my 2005 Hunter 38.
Fuel is a separate monitor on my boat.
 

buddy0

.
Sep 17, 2014
33
Hunter 33 Oriental, NC
Now that my fuel gauge finally works, I thought I'd follow up.

Thanks to senang, I did contact Dennis Ferriello, who put me in contact with his engineer, David Davis, who happened to be the original designer of the sensor. David was a tremendous help in figuring out exactly what was wrong and my options for fixing it. He also offered to sell me a replacement display that would install into the same hole if I wanted to go that route.

I spent some time down the wrong path troubleshooting because I didn't realize that the display only sent voltage periodically to read the fuel level. Argh.

Once I was satisfied that the display was not bad, the options were either to replace the display anyway (with one that reads resistance instead of voltage) or to add a 510 ohm resistor between the power and sensor wires and use a regular resistance based sensor. I did the latter.

One last twist is that you need to use a 0-180 type sensor, not a 240-33 type sensor. Otherwise the gauge will read backwards.