Gas Gage reads full

[digimoose]

People you may have seen this before but perhaps some one can put me onto something that will straighten me out.
The gas gage reads full with a half-a-tank or Moore, I took the sender out of the tank with the wire still connected and moved the float up and down through the whole range and the gas gage pointer mover back and forth just like it should. I looked all over the sending unit and I could not see any way to calibrate the float . It's a 40 gal tank with a "v" bottom 5" deep from bottom to top where the sender in screw down . soo it looks like I need a sender that I can calibrate with a 5" swing that use's through screw bolting down.

any help out there would be appreciated :: digi moose

[jethro1]

Get into the 21st century. Ditch the mechanical style fuel sender and get something that is state of the art. Try these folks.

http://www.centroidproducts.com/

It is all electronic and not much more expensive than the old outdated style of fuel senders. Once you have used one you will wonder why you waited so long to get one. It can be calibrated to be dead on when the tank is empty and dead on when the tank is full. It also reduces if not eliminates the fuel gauge needle bouncing around when the tank is less than full of fuel.

[dragn3]

you can buy new sending units at your local marine store that are adjustable for 25 - 40 bucks depending upon model. the sender you have might not be the correct one so testing it might not do any good but the way you test a sender is you take one of the wires off the sender and touch it to the other wire that is still connected to the sender and if your fuel gauge moves then it is bad and if your gauge does not move then it is good. if the sender you have is not adjustable then it sounds like you need to buy a new one. hope this helps you.

[digimoose]

jethro1;
Thank you I never saw this before, It looks like just what I need I'm going to order this today.

thank you digimoose.

[Wheel House]

Take the wire loose from the sending unit, if the gauge still reads full take the the wire loose from the back of the guage.If the gauge returns to empty you probally have a short somewhere in the wire. Try running a new wire from the gauge to the sending unit. If this does not correct the problem I suspect that the sending unit is faulty. Hope this helps.

[kerno]

The gage reads full when the sender lead is shorted to ground or has little resistance. The sending unit acts as a reostat, reading about 33 ohms when full and 240 ohms when empty. Since your sending unit moves like it should, something is shorted inside the sending unit, meaning it grounds internally when the tank is at over a half. I've run into it before and found that is you take the ending unit apart, you'll find that the contact arm inside is out of line and runs up the coil to about the halfway point and then jumps off the side, shorting itself out. They are pretty simple devices and if you take it apart and can't fix it, you can always buy the electronic version.