Fuel gauge waaay beyound R

[Mless5]

My brother's e30 has a funky fuel gauge. It was dead, turned out to be loose ground. Now it works, but when going empty it runs all the way to the left before the light comes on. It goes past red zone, past the light.

Any thoughts on this?

Thanks!

[Ablice]

Show me picture of where it sits with the ignition off. (where the needle rests).

Next possibility, although we'll wait until ^...the beloved SI board.