MEP-803A Pegs fuel gage all the way down past empty.

[Ray70]

I just got done fixing one of my MEP-803A's that was randomly pegging the fuel gauge all the way to the left.
It was pegged down when I bought it, so I swapped in a known good gage out of another 803' and it seemed fine.
I load tested the machine for about an hour, then shut it down. Next time I looked at it the gage was stuck down again.
Turns out that what is happening is that if you have 24V+ on the power wire and 24V- on the wire going to the mounting bracket stud and you suddenly loose all resistance to ground on the sensor lead ( open circuit ) the gage will peg itself hard to the left and the needle will get stuck against the side of the gage body.
If you remove the gage and whack it against the palm of your hand , or something else... you can shake the needle loose and the gage should be fine.
In my case the sending unit inside the tank is dirty and seems to have multiple dead spots in it. It is currently soaking in cleaner and is about 90% functional now. Just 2 last dead spots that need more attention. Getting it out of the tank was a joy! Couldn't get it through the hole but found that removing the top half of the bracket and the top screw from the sensor body made it able to pull right out, no need to gut your arm wedged inside the tank!
If for some reason I can't get if to work 100% I know I saw a thread on here somewhere with a sender PN that is available on Amazon... if it comes to that.

 

[boatman69]

Graduate to this century . About 40 bucks if you shop around.
http://www.wemausa.com/sensors/level-FuelWater.shtml#.Wbxm_NkpDZE

 

[Ray70]

Cool thanks. Pretty sure that's the same one I saw that they say is available at NAPA and Amazon.

 

[dav5]

Graduate to this century . About 40 bucks if you shop around.
http://www.wemausa.com/sensors/level-FuelWater.shtml#.Wbxm_NkpDZE

Boatman, that looks like a way more solid sensor. Have you installed one? Can the flange be removed for installation? Thanks Ted

 

[Daybreak]

Graduate to this century . About 40 bucks if you shop around.
http://www.wemausa.com/sensors/level-FuelWater.shtml#.Wbxm_NkpDZE

Howdy,
That looks like the new fuel level sensors that are in all the AMMPS generators now. Except they do not have the external float.

 

[boatman69]

Okay for starters no the flange is not removable. Highly reliable I have installed hundreds of them they've been in higher-quality boats for 20 years. I fit them in very tight spots. All's you need to do is Slide the magnet up and you install. The style you're looking at on the new amps units is also a good, works on slightly different technology but you're not going to get one for 40 clams. It works for an 802 I don't know about an 803. I would think it would wedge in there. You can test it with a half inch or 5/8 dowel rod cut to the correct length. And it is almost surely based off of a digital signal. Measure the depth of your tank and subtract half an inch that's your length. If it's very close it can be less it just cannot touch the bottom of the tank.

 

[CT-Mike]

Boatman,

On the link you provided, which particular model are you installing in the -802s?

Thanks.

 

[boatman69]

Measure the tank top and I will give you the correct part number. From outside the top to the bottom exact measurement

 

[CT-Mike]

Measure the tank top and I will give you the correct part number. From outside the top to the bottom exact measurement

Ok thanks.

 

[boatman69]

Don't bother measuring I didn't realize 802 I just got to look up that's what I have. Give me half an hour.

 

[CT-Mike]

Don't bother measuring I didn't realize 802 I just got to look up that's what I have. Give me half an hour.

I have an -803.

 

[boatman69]

Wema - 151323
That is 5.5 inches. Six is pushing it the way the top sags.
Google around for best deal.

 

[boatman69]

Here you go you won't beat this price https://www.fisheriessupply.com/wema-usa-sss-ssl-flanged-fuel-water-tank-sensor

 

[CT-Mike]

Wema - 151323
That is 5.5 inches. Six is pushing it the way the top sags.
Google around for best deal.

Thanks for the help.

 

[boatman69]

Sure anytime. Glad to be of help.

 

[Ray70]

Cool, I think I'm going to go that route on the next one I get with a bad sender. Hopefully the resistance range is the same as the stock sender.

 

[boatman69]

Of course it is you think I would tell you to buy the wrong stuff?

 

[Ray70]

Hey guys, ( CT-Mike in particular ) I've come across another 803 with an unrepairable fuel level sensor so I'm going to try one of the sensors boatman69 mentions above.
My question is length... on the 803 it looks like the tank's step-down is right at the side of the fuel sensor hole, so I'm wondering if you guys go with an 8.5" sensor on the 803's and 5.5" on the 802 ( because the step-down on an 802 is in a slightly different spot )
My concern with the 8.5" sensor is that if the sensor sits crooked ( due to distorted plastic tank top ) the float could rub on the side of where the tank steps down and possibly get hung up.
Or do you guys just go with the 5.5" on both models and not worry about measuring the fuel in the lower step of the tank?

 

[jqc99]

I'm needing to replace the sending unit in my 803. Did you end up going with the 5.5" or 8.5" unit? Thanks for the help!

 

[Ray70]

I have used 3 or 4 of the 8.5" senders on the 803's. The float is very close to rubbing on the side of the step down portion of the tank, so I made a plastic ring slightly larger than the float diameter to press onto the very bottom of the rod to prevent the float from touching the side of the tank.
If you use the 5.5" you won't have any interference issues, but your gage reading will be off by probably 1/4 tank.
The SAE bolt pattern is such that you put the wires pointing to the right ( oil filter side of machine ) when looking at the tank to make the hole pattern line up.