Gas gauge calibration

[JeffsJeep04]

I was changing out a few bulbs in my instrument cluster and bumped the needle on my gas gauge. I tried to put it back where it was, but now it seems to be reading about 1/8 tank high. Does the position of the needle with the power off have any bearing on the reading?

 

[bot0611]

I have no clue, but one i was changing my oil pressure gauge and i accidently tipped the gas gauge but i remembered where it was so i took it off and placed it in the right spot although i thought then it would read 1/2 qrt more of gas. but hear from others febore you mess with it.

 

[4xcrazy]

I believe it should go back to where it's suppose to when you turn the power back on.

 

[JeffsJeep04]

I guess I'll see what it does over this tank. Usually when I fill until it kicks off the needle is around a quarter inch above the full mark. This time it is a good half inch. Same gas station and pump I usually use.

 

[diesel4me]

The gauge can read anywhere on the dial with the key off,but usualy it stays close to the actual level in the tank,in my experience..the gas gauge is just two coils of wire ,with the needle "balanced" in the middle,kind of like an ampmeter--the sending unit increases or decreases the amount of current in one coil or the other ,depending on the amount in the tank--the "full" coil attracts the needle more the full mark,when the sending unit sends it more current than the "empty" coil has,and vise versa when its empty...I've never bothered trying to calibrate one,I just get another gauge from the salvage yard if I have one that wont read correctly..most all of my trucks had very accurate gas gauges..

 

[British Slave]

Take the gauge out and check to see if the nuts holding the resistor in place are tight.

 

[Blue85]

These gauges don't have springs, so they don't move unless there is voltage present. When you turn the key on, you will see where it wants to be. If starting over, I like to to calibrate it to an empty tank. This is a lot harder to achieve than a full tank (bring a gas can), but it's more important to know when it will run out than "how full" is full.

 

[JeffsJeep04]

I always fill up at a half tank anyway, can't deal with the pain of a $120 fill up. A fuller then usual tank would explain both the higher reading and the mpg drop on the last tank.