engine temperature gauge doens't work
 

Today I got my car back from my body work specialst, when I was driving it I noticed that the gauge that shows the engine temperature didn't work at all.

Apparently the genius disconnected my battery because the alarm kept going of, my guess is that there was shortcut on one of the plugs.

But I have no idea which one is responsible for the engine temperature gauge? Or could it be another problem?

Thanks,