Wiring Diagram for Instrument Cluster

I have a fuel gauge that is not working. I have confirmed power is going to the sending unit and the next thing is to pull the instrument cluster. I wanted to start out by testing to make sure power and resistance is getting to the gauge but do not know what wires to check. Most likely there is a problem with the gauge itself as it stays on full wether the sending unit is plugged in or not.

Additionally, if anyone has had this problem before and knows how to fix it, I would appreciate any information that can be provided.
Thank you

Check the service manual

Thanks. I really appreciate it.

It does sound like the gauge might be bad. You can download the factory service manual from the link in my signature. The troubleshooting procedure for both the fuel gauge and sending unit is on p. 25-116. It's fairly straightforward and shouldn't require any tools beyond what you already have.

There is a circuit schematic with wire colors and a description of how the circuit operates in the Electrical Troubleshooting Manual (also available in my signature). The fuel gauge section starts on pp. 146-148. There are also pics of the wire connections and locations that should be of enormous help.

Let us know what you learn.