Fuel Gauge

[Guest oldman]

Fuel gauge playing up what voltage should i have at sender unit checked it i have 7.5 volt at unit should this be 12 volt cheers ray goddard

[Foz]

Hi Ray, don't know which sender & gauge you're using but usually the sender is little more than a variable resistor to ground. The more fuel in the tank the lower the resistance (and lower voltage across it) thereby leaving more of the 12 volts battery voltage across the gauge. Hope this makes sense.

When you say it's playing up what's it doing exactly ? If it's wandering about does it go higher than it should or lower ?

Steve

[Guest oldman]

Not showing any fuel on gauge

[Guest Ian & Carole]

Just to comfirm that you have not got gauge failure, take the wire off the sender unit and make it good to an earth.

Turn on the ignition and you should get a "tank full" reading.

HTHs

[IanS]

Most electric guages expect to be powered from a regulated supply.

The original ford dash instruments had a built in 8 volt regulator powering fuel guage and water temp guage.

This avoids readings moving when moving between tickover with everything on and revving the balls off.

So voltage at sender looks good.

The sierra fuel sender earths through a seperate wire to a bullet connector on the metal of the mounting.

Have you connected this to a good earth??

 

Ian