Two Type 94 high-angle fire-control directors, one on each side of the ship, were fitted to control the Type 89 guns. Each director mounted a rangefinder. When "Jun'yō" first commissioned only the rangefinders were fitted and the directors were added later. Four Type 95 directors controlled the 25 mm guns and another pair were added in early 1943. Early warning was provided by two Type 2, Mark 2, Model 1 air search radars. The first of these was mounted on the top of the island in mid- to late 1942 on each ship, and the other was added during 1943. This latter system was fitted on the port side of the hull, outboard of the rear elevator. A smaller Type 3, Mark 1, Model 3 air search radar was added in 1944 on "Jun'yō".