fuel gauge dead

[5series]

my fuel gauge reads empty on full tank. i've already swapped out the fuel pump and sending unit, still no change. don't think it's a broken baffle issue. i've grounded the wire(s) that sends signal to the gauge/needle expecting it to move but nothing happened. what else am I missing

[9-3 Aero]

The reply based on the 9-5 wagon, as MY of car in question is not given.

Measure the fuel sensor voltage at the disconnected fuel pump and sending unit connector, pin #4, positive 12V or a little less, depending on the internal resistance of the multimeter, and pin #3, gnd. A (good) voltage reading here indicates unbroken contact towards the Main Instrument Unit (MIU).

Measure resistance of the sensor: Empty tank: 40+/-1,5 ohm, full tank 250+/- 6,5 ohm.

Grounding the signal wire may not have been a good idea, as the input circuit of the MIU normally has a minimum resistance.

[5series]

Thanks for the reply. Ok, really suck with electrical stuff. Can do just about every other thing though. so here we go, you want me to disconnect the plug and check for 12v volts on pin#4 which I think is the red/orange and black wire. then ground pin#3 which is the grey/white wire next to it.

The reply based on the 9-5 wagon, as MY of car in question is not given.

Measure the fuel sensor voltage at the disconnected fuel pump and sending unit connector, pin #4, positive 12V or a little less, depending on the internal resistance of the multimeter, and pin #3, gnd. A (good) voltage reading here indicates unbroken contact towards the Main Instrument Unit (MIU).

Measure resistance of the sensor: Empty tank: 40+/-1,5 ohm, full tank 250+/- 6,5 ohm.

Grounding the signal wire may not have been a good idea, as the input circuit of the MIU normally has a minimum resistance.

[9-3 Aero]

Connect positive multimeter probe to the plug, pin #4, (presumably) yellow/white (gauge sensor and power), for positive 12V or a little less, and negative multimeter probe to pin #3, grey/white, which is "gauge sensor gnd". That's it.

NOTE: This refers to a MY2001 9-5, as you have not confirmed which car is in question!

[5series]

Ok, finally got around to checking for 12v and pin #4 and got no reading,

[9-3 Aero]

Car in question / MY