Raw values from level tank

[manolo.lezl]

Hello.

I've been testing and calibrating the fuel level sender. It's a 240-33 Ohm one and I have a behaviour I don't know if it's right.

Header tank is 7 liters and I get these values every 500 ml (ml:raw value):

0: 3908
500: 3908
1000: 3908
1500: 3908
2000: 3908
2500: 3908
3000: 3908
3500: 3908
4000: 3908
4500: 3908
5000: 3908
5500: 2730
6000: 2730
6500: 1938
7000: 1938
7300: 1930

The value only changes twice. Fron 0 to 5 liters, the raw value is always the same.

I have an analogue indicator too and it changes continuosly.

Any hint about this behaviour?

Thank you.

Connections are as follow:

[Olivier]

Hello.
Disconnect the analog indicator. It is forcing about 6V to the RDAC FL input through it's internal resistor bridge

[andynoiseboy]

Is the Fuel Level Pull Up resistor enabled on the DIP switch?

[manolo.lezl]

Hi.

I've tried both positions for FL1 DIP switch.

[manolo.lezl]

Hello.
Disconnect the analog indicator. It is forcing about 6V to the RDAC FL input through it's internal resistor bridge

Oops.

I didn't saw your answer. I'll try tomorrow. Thank you.

[manolo.lezl]

Solved.

I installed a switch to select one or other level gauges. Normally connected to Efis and the analog one as a backup/check.

Regards. Manolo.