Self-illumination.

All mechanical signal devices shall be self-illuminated when in use at the times mentioned in section 321.384 . [C39, § 5034.14; C46, 50, 54, 58, 62, 66, 71, 73, 75, 77, 79, 81, §321.405 ] Referred to in §321.1 , 456A.12