I have a Bav 44. My fuel gauge also failed. The sender unit is a simple float that changes the resistance. 180 Ohms sounds correct.
Turotuss made my original gauge. They are available in Europe
. Down Under the freight cost is excessive. So, I just bought a standard fuel gauge (50mm diameter) locally for a 180 Ohm sender.
Plugs straight in.
Bad news is the Turotuss is a graduated gauge to match the triangular tank.
Normally, half full is in the middle of the gauge. On the Bav’s using Turotuss half is where 3/4 normally is.
So, with a standard gauge you need to remember 3/4 = 1/2 full. And 1/2 on the standard gauge is about 1/4 of the tank.
Hope this helps.