So about the only thing that they installed that might have affected the temperature gauge is the alarm. When I worked at a shop we would pull the bezel around the instrument cluster and reverse mount the LED for the alarm. I would hope that they did not pull the cluster to tap any wires back there as all the ones you need are in the driver kick panel and behind the head light switch (flash the parking lights when arming and unarming). Anyhow, if its a reputable shop then I would say no but hey one of our senior installers put a screw through a fuel line once so anything can happen.