Fuel gauge problems

[Chummy]

I have searched through the forums and have found little answers concerning the issue I have.... So hear goes: Usually the needle sits at a little to the empty side of the 3/4 tank mark but will start twitching around while driving around. I have replaced the board in the cluster, the fuel gauge, and tested a different sending unit. None of these seem to resolve the problem. Looked at an actual BMW wiring diagram for the car and don't see anything that stands out (pretty simple really). Oh yeah when I tried the other sending unit I didn't actually instal it in the tank because if I did I couldn't return it but when tipping it from right side up to upside down the needle would move but didn't have a full swing on the gauge. Anyone have any other ideas?

[benoithnadon]

Read the following article, i hope so it will be helpful for you. Best of luck!!!

http://chevelleengineer.home.comcast.net/~chevelleengineer/fuelgage.htm

[Gregs///M]

Check the cluster grounds above the brake pedal. On a bracket with two 10mm nuts on it. Remove both and clean all brown wires with ring lugs with wire brush. Re-attach.

Also make sure your 7mm nut behind the gauge is tight.