Fuel Gauge

tb_gb

tb_gb

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Jul 26, 2019
22
Hunter 380 Daytona Beach, Fl
On my Hunter 380, my fuel gauge always shows about half full....even when the tank is full, as it is now. Brand new gauge, so it has to be the sending unit. Does anyone have a recommendation for an "easy to install" replacement sending unit?

Thank you
 
jssailem

jssailem

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Oct 22, 2014
21,158
CAL 35 Cruiser #21 moored EVERETT WA
A picture of your tank top showing the sending unit would be helpful.

This is one of the Moeller senders. (ELECTRIC SENDING UNIT W/REED SWITCH) I am using it on my boat. It has worked smoothly and with accuracy for about $90. Comes in different lengths too accommodate your tank.
1671220118261.png
 
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Ralph Johnstone

Ralph Johnstone

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Jan 4, 2006
6,522
Hunter 310 West Vancouver, B.C.
tb_gb said:
On my Hunter 380, my fuel gauge always shows about half full....even when the tank is full,
Click to expand
What does the gauge say when the tank is close to empty ? Will anything cause the gauge to move off of half full ?
 
BarryL

BarryL

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May 21, 2004
1,013
Jeanneau Sun Odyssey 409 Mt. Sinai, NY
Hey,

Before you start replacing things, be sure to check the wiring and the connectors. Over my 20 year's of boat ownership I can't even count the number of times that crimped on connectors are failed. Heat shrink, no heat shrink, good crimps, bad crimps, after a number of years they all seem to fail.

Check at the sender unit in the tank and at any panels, and, of course, at the gauge (which being new PROBABLY means it's OK).

Barry
 
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RoyS

RoyS

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Jun 3, 2012
1,742
Hunter 33 Steamboat Wharf, Hull, MA
There are different sender unit designs. I like the ones that are flexible as there is often little room above the tank for the installation. You have to get one that has the proper depth to match your tank depth. Virtually all the sender mounting ports are the same universal design. Be careful with the orientation of the sender in the mounting port. It will only attach in one direction as the screw holes are not equally spaced.
 
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Rich Stidger

Rich Stidger

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Feb 10, 2004
3,948
Hunter 40.5 Warwick, RI
I have had repeated failures with the type of sender that uses an arm with a float. I have now switched to the vertical tube with internal read switches and after two years have had no problems.
 
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Sailgunner

Sailgunner

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Jun 4, 2004
1,077
Hunter 410 Punta Gorda
Call WEMA. I replaced my sendinig units 11 years ago and all are still working fine. Waste can get stuck but after cleaning works fine.
 
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sailcapt340

sailcapt340

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Sep 26, 2008
558
Hunter 340 0 Wickford, RI
A word to the wise….I‘ve had my fair share of sender and gauge failures through the years. If you contact WEMA be certain you contact WEMA in the UK. The others were “authorized“ manufacturers of their products and the quality control was lacking.
This is a copy of my posting from June 22… There were more but this was the basic one you need for the link….
After my Wema Sensor fresh water float completely deteriorated, still trying to figure that one out. I spoke with Henry at Wema in the UK. He can outline the proper testing voltage and procedure for you. He is really very helpful. hello@wema.co.uk
He can better tell you the major difference in Wema USA and Wema UK. You want Wema UK.
I have an earlier posting from about 2 months ago “Wema Fresh Water Gauge Sending Unit” you can read here for some help.

Also from WEMA…
Here is how to test….

use this method, it comes from WEMA Gauges.

To test the sender simply:
  • Disconnect the two wires on top of the sender.
  • Remove the sender from the tank.
  • Connect the wires on the sender to a multimeter.
  • Set the multimeter to resistance [Ω ohms]
  • Move the float to the top of the sender and take a reading on the multimeter:
  • At the top of the sender (full) the resistance should be:
    • European specification - 190 ohms
    • American specification - 30 ohms
  • Move the float to the bottom of the sender and take a second reading:
    • At the bottom of the sender (empty) the resistance should be:
      • European specification - 0 ohms
      • American specification - 240 ohms

If you don't get the expected resistance reading on the multimeter then the sender is at fault and will need replacing.
 
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Ralph Johnstone

Ralph Johnstone

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Jan 4, 2006
6,522
Hunter 310 West Vancouver, B.C.
Thanks, was not aware of the two different models.

I've had WEMA sensors in both the potable water and diesel fuel for 24 years. The WEMA holding tank sensor was trashed after the first two years. Unless the breakdown in QA has happened since 1998, I will assume mine are the European model
 
sailcapt340

sailcapt340

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Sep 26, 2008
558
Hunter 340 0 Wickford, RI
For me it wasn’t the gauge, sensor or wires. It was the float themselves. They just deteriorated. What was left of the floats, that I could handle without them falling apart in my hand, would register perfectly when moved up and down the tube.
That’s when I learned about the manufacturing differences. Imagine how shocked I was when I took this sensor out and saw that float. Bottom photo is original versus new.
 

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Ralph Johnstone

Ralph Johnstone

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Jan 4, 2006
6,522
Hunter 310 West Vancouver, B.C.
sailcapt340 said:
Imagine how shocked I was when I took this sensor out and saw that float.
Click to expand
Maybe that was their biodegradable model :yikes: !

Now I've GOT to check mine this summer whether UK or US model. How long were your units in service before those failed pictures were taken ?
 
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sailcapt340

sailcapt340

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Sep 26, 2008
558
Hunter 340 0 Wickford, RI
I checked back through my log entries.
First started noticing level reading problems around 2010. Bear in mind, we’ve own our boat since new in January 2000, fresh out of the plant. I even have pictures of the build.
After 2010, the I was in denial for the next 2 years. You know, tapping the gauge, tapping the sensors, cutting the connections and crimping on new ones and hoping. And that worked for a while!
First sensors were replaced in 2012. And they worked for a while. The float’s didn’t look half as bad as your seeing now when I took them out. All was good.
Then I got the encore performance.
This year I found what you see in the photos.
I do have to say that I have never replaced the Waste Tank Sensor. And it works perfectly. Maybe because the float has a “protective” coating on it. And I don‘t really want to look and see.
I think it has a lot to do with with who was building that day and taking parts from which box of parts that were available.
For a while, I did think it was chlorine content in the water for the fresh water sensor, but that couldn’t be for the diesel fuel.
Just luck of the draw I guess.
 
JamesG161

JamesG161

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Feb 14, 2014
7,453
Hunter 430 Waveland, MS
I had same issue with my Wema Fuel gauge as @sailcapt340 . I called Wema direct.

Ans: The old float was not coated correctly.

Result was a design change to prevent the float from ever adsorbing diesel.

My new one allowed me to calibrate my tank to ± 5 gallons in a 50 gallon tank.:biggrin:

Jim...
 
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Project_Mayhem

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Sep 24, 2018
2,631
O'Day 25 Chicago
Not trying to derail this post but I have the same issue as the OP. When is it best to seek the original sending unit for ease of installation and when is it best to upgrade to a different style of sender?
 
jssailem

jssailem

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Oct 22, 2014
21,158
CAL 35 Cruiser #21 moored EVERETT WA
Project_Mayhem said:
I have the same issue as the OP
Click to expand
Your display is showing "Half Full" when you suspect it is more or less than indicated.

First thing I would do is verify if the sender is at fault.
If at fault than replacement is an easy decision. If not at fault, you might choose to replace - or not.

What type of sender do you have?
Traditional?
1671564773566.png

Or new model
1671564815346.png
 
P

Project_Mayhem

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Sep 24, 2018
2,631
O'Day 25 Chicago
jssailem said:
Your display is showing "Half Full" when you suspect it is more or less than indicated.

First thing I would do is verify if the sender is at fault.
If at fault than replacement is an easy decision. If not at fault, you might choose to replace - or not.

What type of sender do you have?
Traditional?
View attachment 211758

Or new model
View attachment 211759
Click to expand
The boat that has this issue is a 1995. It's wrapped up for the winter. To rephrase my question, is one design more reliable than the other?
 
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