Need help with water temperature gauge

[RockBit]

I have not been able to get my water temperature gauge to work and was wondering if anyone can help me.

I have the electronic version of the Smith gauge. When I turn on the ignition switch, it sweeps to the right and returns. The light in the gauge also works when the headlights are on.

There are four wires coming out of the gauge. Here is what they are connected to:

R/W wire from gauge is connected to number 5 red on the harness.

G wire on gauge is connected to the thin geen wire on the harness, which I thinks is the power for the dash lights.

B wire on the gauge is connected to the number 5 black on the harness.

B/W wire on the gage is connected to the sending unit on the intake manifold.

If I start the car and let it warm up, the water temp gauge never moves from cold. Any idea what I am doing wrong?

Thanks.