PURPOSE: To improve visibility for detecting broken wire in use of winker, by constructing both functions of hazard and winker in single unit using digital circuit, minimizing the equipment additionally lowering price.

CONSTITUTION: An ignition switch 22 is shut, when a winker switch 41 connected to either contact point 41L or 41R, AND gate 36 of selecting circuit 34 ON.OFF controls the transistor 39 with a signal of frequency 4/3 Hz, lamp L1 L2 or L3, L4 goes on and off with signal period of frequency 4/3 Hz. At winker opertation, when one of lamp L1-L4 is broken, the selecting circuit 34 turns ON.OFF the transistor 39 with a signal of 8/3 Hz, lamp L1, L2 or L3, L4 goes on and off with this period. When hazard switch 42, 43 is operated, lamp L1-L4 goes on and off with a signal period of 4/3 Hz.