Praet0rian

Hi Guys, Just bought an E36 compact as a runabout but have found the fuel gauge works intermittently. When I drove it this morning the gauge read correctly but shortly after it just went down to the rest position. The low fuel light isn't on. I chucked a multimeter on the sender units, one was 50ohms and the other 100. Is there anything else I can try before I replace the gauge cluster? PS. Can you remove the cluster on a compact without removing the steering wheel? Cheers guys