Does gas gauge read when off?

[Surrey]

I have an 89 bronco II, and I was wondering if the gas gauges on these things typically work when the truck is off?
My reason for asking is my gas gauge doesn't work when its running (reads way over full) and Im not sure if the gauge is reading something when its off, or if its just zeroing off at 3/4 of a tank when it gets turned off. (only noticed it last night, havn't driven enough to move the needle)

Thanks.

 

[5.0 Kid]

I have 2 1990 b2's and both seem to read around 1/2 when off but when key is turned they move up or down depending on whats there.

 

[Ranger Sport Honduras]

they usually stay where it was reading when the engine was ON.
they move when the key is on depengind if u added more gas or took out gas.

or if uve been parked on inclination, when the key is on it will move.

 

[adsm08]

Mine zeroes with the key off. They aren't supposed to stay on to my knowledge. Never owned a car that did.

 

[Surrey]

Mine zeroes with the key off. They aren't supposed to stay on to my knowledge. Never owned a car that did.

That was kind of what I was thinking... My 88 zeroed, and so does my 95 golf. Seems without power it can't take a reading?

 

[adsm08]

Well the gauge works on resistance. It shoots 12V down a line and then through a wiper that rests on a series of resistors along the sender's armature, each corresponding to a different amount of fuel, and back up a signal return line. Less voltage means the needle doesn't have the power to go as high. Try to reach up on top of the tank and just unplug the pump. See if the needle zeroes out then. If so, you have a sender issue. If not, you have a gauge issue. I'm kinda leaning towards gauge issue myself.

 

[p38fln]

Mine just stays wherever when its turned off - Actually, both the fuel and temp gauges stay wherever they were at when it was turned off.

Speedo, Tach, the fake oil gauge, and the voltage gauge all drop to zero

I've got a newer model of course, not sure what the differences are

 

[Ranger Sport Honduras]

Mine just stays wherever when its turned off - Actually, both the fuel and temp gauges stay wherever they were at when it was turned off.

Speedo, Tach, the fake oil gauge, and the voltage gauge all drop to zero

I've got a newer model of course, not sure what the differences are

mine works this way. the 93 we had did it too