Fuel gauge stopped working

[n33k0]

Greetings

The fuel gauge in my truck has stopped working. Luckily I noticed before I ran the tank dry. It is stuck between the 1/4 and 1/2 marks. This past weekend (and for the next few days) it has been raining constantly, and my truck is not very water-proof. Water leaks in to the cab, behind the dash... could the leaks have done something to kill the gauge? If so, where would I start looking for problems?

It had been working for the past year, although it was not working perfectly. The tank looks to be a blazer tank, located under the bed. I would fill the tank until the pump shut off automatically, and the gauge would only read 3/4 full. I'd drive until the gauge reached the short line between empty and 1/4 (which would mean 1/8 fuel left), and refill the tank, but it would only take 11-12 gallons (aren't blazer tanks 20gal?). I've never gotten brave enough to drive it till it ran out of gas to determine if the gauge needle was off or if there was an actual problem with my sender.