Dash Cluster

Have you temporarily shorted the wire at the sender and looked for movement on the guage.

If you check the posts on the back of the gauge with a volt meter you should have about 5 v on both posts. With the sender wire shorted you should have about 5 on one lead and about 0 on the other.

If without the sender wire shorted you have 5 on one and 0 on the other the guage is broken inside.