Temp gauge/sensor/wiring ?

[magnethead]

I was driving back from town today and the gauges were normal (45 PSI/1st temp mark/14 volts) and when i looked down after feeling hot air hit my hand out the window, i saw the temp gauge pegged so i shut it down. The upper radiator hose was hot (first thought was thermostat), the overflow was empty, and the gauge hadn't moved when the ignition was turned off.

We just limped it home, and the radiator has full water in it, but i'm not sure about the gauge..where does the wire from the sending unit go on the back of the cluster? Theres 3 metal terminal type things that have ~3/16" holes below and left of the light hole, but they appear to not of had a connector on them based off of previous imagery.

I have the feeling it's electrical because when I pulled the gauge cluster, who knows what may have been accidentally pulled loose (Already found out i yanked the speedo cable out of the connector under the hood, tape fixed that).