Help on fuel sender problem

I have had to replace the sender on my 87 E34 twice in 9 years. The last one was installed 2 years ago. I now have an intermittent FULL indicator problem. If reads beyond full for minutes to many minutes to hours after the switch is turned on. I have done the usual diag (seen elsewhere on the net )to confirm that the the gauge is ok, resulting in an indication that the sender is faulty. I checked for loose wires. I can sometimes remove the wires to the sender and replace them and it starts working. I removed the sender and it checked ok for ohms when moved up or down. I even added a weight to the arm of the sender to make it show empty but it still showed full. Later, all of a sudden it worked.

If it goes like the last time, I can replace it with a new sender and it will work.

My question is why is the sender going bad so often?

Go Electronic !

I replaced my Fuel Tank (4) years ago and the Builder recommended to go with a Centroid Electronic Fuel Guage System (www.centroidproducts.com). They are compatable with many Guages, Work Great and the Customer Service was really helpful. Would never go back to Mechanical Sending Units. They actually Break Apart in rough seas. That's why the Commercial Tank Builders use Electronic Sending Units :nerd:

Finally after several frustrating years, I found the problem. It was the connection to the gauge. Only after taking the gauge out and vigorously moving the wiring around did I find it. It was at the gauge connection. Hard to believe that it would make/break connection with no boat movement after a variable amount of time.

I may be replacing my fuel gauge soon and discovered that there are two different resistance ranges used for these gauges; you have to make sure the sender and the gauge match. (Since my fuel tank/sender were replaced I'm not sure mine do.) I also read that even a small amount of corrosion at the connections can change the resistance and cause the gauge to give inaccurate readings; which sounds like what might have happened to yours.