New LS1 Owners - Newbie Tech - Why isn't my temperature gauge working?

I checked the sensor on the driver side head and it appears to be fine AND I just replaced it last month or so. I don't know if this could've caused it, but over the weekend I broke the wire that plugs into the alternator. I did rewire it and soldered it back together. Could this be the problems?

Unless there is a short somewhere or a break in the wire to the sensor try replacing it. I had a bad one that acted up a month after I put it in.