Gas gauge reads half when empty

[moranda]

I have the stock gauge in the jeep. What happens is that half on the gauge is empty and full will just be full for a long time until I am under a half a tank and then the needle will start to move. I am asking because I am going to be doing a lift kit and that just so happens to be a great time to drop the tank if need be. Is this a sending unit problem or is this something else? I know I have gremlins in the electrical so that doesn't help.

 

[gutthans]

The fuel sender arm probably needs to be bent. These senders work by transmitting current through a resistor on the bottom of the unit. The arm brushes across the resistor, changing the level of reading voltage depending upon where it is touching the resistor area (at least in the senders I have used). If it's reading half-full at empty, then it is likely too high up in relation to the resistor...bend it downwards (at the point where it crosses the pickup area)so that the contact point of the arm is closer to the bottom of the resistor segment when the float is dropped to the bottom of the tank.

IIRC, the top point should create the least resistance in the circuit (reads 'FULL") and as the tank level drops, the sender arm goes progressively lower on the resistor creating more current resistance and the gauge 'sees' this as a lower reading (empty). Typically, the float is aligned in such a way that the position of the float in the liquid gas correlates to the amount of reading current generated. But sometimes in adjusting the float to bottom out properly you can move the arm's relationship to the pickup too much and it no longer correlates with the true position of the float. If you can't get it right...another sender is pretty cheap.

However, if your contact IS at the end of the resistor and bending won't help, then it's reasonable to guess that the sender needs replacing.

 

[graycj7]

What company have others had good results with when buying a new sender unit. Thanks for any help as I think that I need a new one.

 

[IOPort51]

What company have others had good results with when buying a new sender unit. Thanks for any help as I think that I need a new one.

I can't wait to hear if anybody has found a good one. Mine sort of works, on the second new sending unit, but truth be told it is a piece of .

 

[gutthans]

What company have others had good results with when buying a new sender unit. Thanks for any help as I think that I need a new one.

Yea, sure....My guess would be anywhere you can get one NOT MADE by OMIX. Frankly, I don't know if ANYONE else is making them now...but if they were, and it wasn't produced in China...I'd get it. Crown is a slightly better choice if available. NAPA would be an acceptable unit as an example, but I don't know if they still market the part.