My sending unit on my 06 Ambassador went bad and I got one directly from Centroid. I accessed the sender by removing 2 screws from the bottom of the fuel door panel and swinging it up. The sender is located on the top drivers side of the fuel tank. Held in with 5 screws if my memory is correct and then lifted out the top of the tank. Be sure to label where the 3 wires are connected before removing them. This is not a difficult project. I think the sender was about $70.
Blessings kdk