[vectorit]

There is only a single lite brown wire that runs front to back for the sending unit, it has a clip style connector that connects to the sending unit and has a plastic cover. Often times this connector loses it's connection, and can cause wacky behavior on the gauge.
There is a black wire that comes off the sending unit, and that one is bolted to the chassis for ground.

For the front fuse block, I don't remember anything had to be connected. Since it is all handled by the harness that comes down the A pillar, and has a big plug that connects to the fuse block.

Have someone watch the gauge as you move the wires on the sending unit with a wooden dowel, you can do this from the passenger rear wheel well.
Careful of the brown wire connection, like I said it's kind of a fragile connector.