Gas guages gone wild..

[wakeboarddrumma]

Yesterday, I put about 3 gallons of gas in my truck, when i had about an 8th of a tank, and my gauge showed me have 5/8ths of a tank afterwards. So i drove down the road, got a bite to eat, and came back outside, and saw that it was back down to 3/8ths where it should be. Why did this happen

[jamon8]

check the ground for the sending unit and the resistance on the wire that connects to your gauge.

If you havent done it in a while it is a good idea to clean all the grounds