I've been working on this one for a while. 99% sure its not sending unit as other have mentioned. Already cleaned it, but there always is that 1% chance.

The reason I do not think it is the sending unit is that after cleaning there was no change in gauge behavior. However, after soldering some components on the cluster board there was a dramatic (and more accurate) change.

So fast forward to this weekend. I replaced the three resistors on the board. The old ones read between 68 and 75 ohm. When heated up with a hair dryer, they went up and down with resistance.

But with new ones, the gauge does not still read correctly. However, its a little more accurate. Once operating for a while, it starts to fluctuate. I think the fault id the potentiometer. I ordered one, but its the wrong size.

Can anyone help with identifying this exact part?

Attached Thumbnails

 

__________________
1991 560 SEL / 185k miles
1992 750il / 17k miles - project car