Gauges and cluster light only work with lights on?!
You want to be using the bottom two probe sockets, and you want the knob pointing to "200" near the bottom, right next to the off-on switch
(Our instructors in U.S. Navy "A" school, circa 1968, Treasure Island, used to say, "make sure the oh en -- oh eff eff switch is in the oh en position" LMAO)