The temp gauge unit is at the rear of the head on the driver's side, its small and tucked in there pretty good. Its tucked right up close to the valve cover, next to the last valve cover bolt on the driver's side,right behind the injection rail, it may have a blue connector on it. The one near the thermostat is the temp sensor. If you can't find it, look for a disconnected wire dangling near the firewall, maybe is just disconnected.
2013 WRANGLER SPORT 2 DR., V-6 ,AUTO,HARD TOP
)1994 Jeep Wrangler 2.5L, Bestop top
/w steel half door and slider windows
5 speed, 2.5" lift, 31" tires,rack lights