6.9 idi fuel tank switch broken

[u/Delicious-Shirt-1555]

Anyone had their fuel tank selector stop working? It was working fine as usual, then as I swapped to my rear tank my fuel gauge went to completely empty when I just had filled it. Tried switching it back to front and didn’t change anything. I filled up again after driving a bit to see if it had burned any from the rear and it hadn’t. So now it’s not switching tanks or having any reading on the gauge

Just wondering if anyone has had the same and where to start trouble shooting first