Ok, I just picked up the boat with a full tank so I didn't notice anything wrong until about half way home when it wasn't moving. When the ignitions are off the gauge goes to empty. When you start up, it moves to full and stays there.

Where do I start to look for the problem? Does it sound like a gauge problem or the sending unit? I looked for access to the fuel tank, but can't seem to see it through the floor locker or the engine compartment.

Thanks.

use a boat for a while and check if fuel level on gauge start going down
looks to me that tank is filled above "default" max

 

Charlie,
You sure it is not one of them new never empty tanks (Grin). How many tanks does the 280 have?

 

It has one tank that holds 127 gallons.

 

Charlie,
I had a float switch sticking on one of my tanks last year. I found the access to it and started to replace it. Then I thought where is my hammer? I tapped on the top of the tank and it's worked every since.
I think in my experiance Float switches are usually the culprit. The crude thats in a fuel tank would scare you.
Hope you find the problem.
Jack

 

I quickly looked for access to the tank and can't find it. According to the maual, the tank is centered between the engine compartment and the floor storage. But, you can't get to the tank from either. I pulled the carpet up and didn't see any access. I'll be happy to to give the hammer method a try.

 

I know we have two completly different boats but I can't imagine there not being an access port to the top of the tank. My access port was a 6 inch screw plug. The ones that have the indentations for your thumbs to unscrew it.
Jack

 

I'll look again. Thanks.

 

Ymmm. Don't remember that access port on my boat. . .

. . but how much fuel did you burn? On my boat, I have to burn at least a 1/3 of the tank before the gauge moves. And then it moves. It reads just about E with 1/3 fuel.

I generally gauge fuel level more by "hours" than using the stupid gauge.

 

I burned 60 gallons and it still read full.

 

Ok . I looked at my boat - it has the same port that wjatshisname describes! (darn cheap whiskey - can't type straight and the stupid iPod ain't helping!)

Yeah - at 60 gallons down, my boat reads about 1/4 full.

 

I found the access to the top of the tank. Pulled on the wires to check the connections, and gave it a few taps to see if it would free up the float, but no go.

So, what is involved to change the sending unit? It doesn't look like too big of a job, but I want to everything covered before I attempt it. How much is a sending unit?

 

I had the same problem last year. I was told that if you take the sending wire coming off the gauge and touch it to ground, you should see your fuel gauge on your dash peg all the way to full. This way you know your gauge is full.

I stopped in our local sea ray dealer and I picked up a universal sender unit. Basically it is longer then needed, so you just hold it up to the other one, and then you cut it to length and you adjust the part where the arm rotates about to the proper height. It is a real simple job. I think the universal sender unit was like $35-40.
I remember a place out of Florida that made a lot more accurate fuel sending unit, however they weren't cheap, and you had to send them someone info and they built it to your needs. I think it was http://www.centroidproducts.com/. I Just went with the universal one cut to length due to time and needed it done asap.

Just remember how you get the original sender out, and pay attention to which direction the float is pointing in the tank now. You will need to put the new one back in the same way and have the float pointing the same direction in the tank.

 

My dealer cannot locate the factory fuel sender, 14 1/8", part #760694.

Anyone know a good substitute? WEMA? Mueller?

 

i would like to thank you all for this discussion. i was having the same problem. i had run for 2 hours on two different days and the gauge wouldn't move. i used all the troubleshooting techniques you suggested and found out. i just get good gas mileage. i finally took it out for mothers day and got it down to half a tank. it took 4 hours but hey i'm not complaining.

 

Unfortunately, I was not that lucky. I replaced the sender with a universal and it still read full. So, I put back the original.

Now, where do I start looking for a ground problem?????

 

Unfortunately, I was not that lucky. I replaced the sender with a universal and it still read full. So, I put back the original.

Now, where do I start looking for a ground problem?????

Did you check the ground on the back of the guage. Plenty of I tube instructional deals showing how to determine it's the gauge or the sending unit.

 

I'm not sure if you fixed the problem yet, but I am having issues with mine. Heres what I would suggest. Take the sender back out and measure the resistance across the 2 connectors. Sweep the float up and down slowly and look for the value to change. Now remove, or access the back of your fuel gauge and jump the ground terminal (one on the base) to ground and the center terminal to the gauge input. Be sure the key is on and the gauge is able to read and move the arm and see the gauge reaction. The problem with most marine gauges is that because they are universal they stay at full for a long time and drop like a rock under 1/4. It due to the long length of the arm. The best kind have a tube with a float that accuratly measure the total sweep. Hope this helps a bit. Just for background, all a sender is, is a variable resistor. Therefore all the gauge is doing it dechipering the resistance change. If you put the arm at full and empty, there should be a sweep value. Say 90 Ohms at full and 0 at empty. Thats why people say to ground the wire and watch the gauge. Unplugged(highest resistance) should be full and grounded should be empty( no resistance) In this example.

 

Did you find your problem? I have the same problem on my 280 DA and I have not began to look for a solution. The hammer trick sounds like a good start.

Jerry

 

Sort of...I tested the new (universal) sending unit outside of the tank and the guage moved up and down when I moved the arm. So, I took out the old sender, and installed the new one. One problem, after I put it in the tank, it stopped working. I have not had time to revisit the problem. I keep the tank full for now.

 

Hi All,

I also have a problem with both mine. One side works from half way down, the other does not do anything anymore. My first thought was that the old float had become bad and is not floating anymore. I think the sending unit is working, at least on the one side.

I have not opened it up yet but what kind of floats did they use 20 years ago? Can I use a cork??

Thanks for any help,
Dean

 

Hi, I’m having a similar issue! My tank on my 180 bowrider is saying full! I used a after market fuel sender and it done exactly the same. I moved the sender up and down and got nothing on the gauge except it saying full tank. I was then told I needed an American sender due to the difference in ohms so that arrived yesterday and I’ve installed today and it’s still doing the same?
HELP lol

 

Gauge and sender must have the same ohm range. Ground the sender wire, the gauge should go to empty. If it doesn't you have a bad gauge or broken wire.

 

Hi I know this is an old thread but I’m having the same issue. My 2008 DA38 is showing full tanks on Port & Starboard and on the Vesselview display. I can’t even get to the senders they are buried so deep into the engine compartment. I have V drives so the space is limited. I’m suspecting it’s either a ground issue or the ultrasonic floats are bad. Any ideas please?

 

Thanks