questions regarding sensor next to thermostat

so i tried doing a search but i couldn't find anything relating so i thought i'd ask the question myself... i'll try and post pictures of what im talking about later tonight

Last week when driving home the headgasket blew so over this past weekend i pulled off the head. in my rush to take the head off (and my first time doing it) i forgot to unscrew the sensor that is right under the thermostat and ripped out the wire that connects to the head of the bolt. I was wondering if this was the sensor for the temperature gauge or is it just a warning light? also... because it wire ripped off near the head of the bolt how would you go about fixing it? any advice would be greatly appreciated

That is the temperature sender for the temperature gauge on the dashboard. I bought a new one last year for under $15 at O'Reillys, special order.

Note: I had to re-use the metal gasket for it, it doesn't come with one (now THAT'S cost savings for the manufacturer !!!).

It's up to you if you want to try to solder a terminal onto your broken sending unit, just don't know....

Solder and heat shrink tubing to fix the wire, new sensor for the gauge. Is easy fix