Fuel gauge

[Spike2450]

Hi All
I've recently replaced my fuel gauge and sender, i dipped my tank and know it is half full.
With ignition on the gauge is showing empty but it is only with the revs say above 2000 rpm that the gauge shows the true value, i.e lower revs lower value. Wondering if there is a bad connection somewhere?
Any help is appreciated.

 

[Barnacle_Bill]

Re: Fuel gauge

That is strange. Check the voltage at the gauge. It should be very close to battery voltage. Then check the wiring at the sending unit. Especially the ground.

 

[wire2]

Re: Fuel gauge

A fuel gauge is actually a dc voltmeter in series with the variable resistance of the sender. 12 volts should split in 6v + 6v across the gauge and sender at ? full tank.

One requirement for it to work properly, is the sender must be matched to the gauge. If it's a marine sender, it should be the right one. (Automotive have several resistances).

One other thing to watch for, a lot of gauges have a built in regulator that sends 9v to the sender. That's done to eliminate gauge fluctuation between 12v of ignition on/idle to 14v at 1k rpm.

Take some voltage readings from the gauge & sender and post again.