Not sure but medyo impossible na mag kasama sa fuse unless indicated sa fuse box. Puputok fuse niyan bago flicker head unit. If I were to guess, mali wiring, kulang current pumasok sa head unit pag may a/c. My guess is the ground.

Try mo gamitan ng test light yung ignition and ground ng head unit, pag mahina, test light iginiton to body ground. Kung lumakas ilaw, ground.

If same, ground ng head unit then ignition wire to positive battery. If lumakas, kulang supply ng current. Kalasin muna wire harness ng head unit baka may madamay sa positive test.