Fuel Gauge/Sender Problem

[whiteyvt]

I have a 2001 28 engine box model with a Centroid 3-wire sender (original I assume). When I flip the fuel gauge switch on the needle it bounces up to half and then back to empty regardless of how much fuel is in the tank. I've exposed the sender and cleaned to contacts but no change.

Gauge vs sender problem? Time for a new sender? Should I use a different type? Any thoughts?

Thanks for any help!

[RobS]

The fuel gauge is a standard "Teleflex type" gauge - Empty 240 Ohms to Full 33 Ohms. Do you have an ohm meter to test your sending unit? The ohm meter POS goes to the sender terminal and the NEG to a good ground. Depending on your full level you should be in the range I referenced above. To further the test top off the tank and you should get a reading of ~33 Ohms. I've posted more than once on this subject, have you used the "Search" function ?

[whiteyvt]

Thanks Rob - I have seen some of your other posts which have gotten me as far as I have. Have you had good luck with your replacement?

[RobS]

Replacement Centroid sender or replacement boat? Yes x2

[catalina_mike]

My new gauge is as inaccurate as the old!

[whiteyvt]

So Mike - if i'm going to go through the effort, should I replace it with something else? If so what?

[catalina_mike]

Tried to respond yesterday using my phone and epic fail after three times waited until I got home..

I would get the best level sensor you can after measuring your tank. I get over 1.5 NM per gal so I use that for forecasting range. My gps has a trip meter I reset and log my time and miles with gallons to form a good tool to use. My gauge has never been accurate and it clearly was the sender not the gauge. If I ever have to get into the tank I will replace it all.

[RobS]

Mike when you say "inaccurate" do you mean erratic or consistently inaccurate? If it is a Centroid sender it needs to be trimmed to the proper length upon install (nothing is safe to assume to have occurred right or wrong at the Albin factory) and then there are two calibrations adjustments, E and F. I had the back deck up at one point to reseal it and the sender was cheap enough so I put in a new one and rewired it while the easy access was there. It was dead accurate 100% of the time.

BTW, When I had the deck off I made this dimensional drawing of my aluminum tank (made by Luther's Welding in RI). The cross section with the V is important when figuring "theoretical" tank depth..

[catalina_mike]

Agreed on the calibration... The gauge seems, so far after 3 tanks of fuel to be consistently reading but inaccurate so adjusting the pots will fix it. 1/4 tank means you need to get fuel the previous owner told me.. I'm not going to find out for sure. However the Commodore wanted the NuTeak on the deck so future access is limited to the sender at this time. It wasn't a big deal to me because I see a flow scan someday in my future...