The invention provides an automotive lighting unit for detecting electrical characteristics of light emitter diode component. At least one light emitter diode light source is selectively disposed on any one of at least one circuit channel of at least one drive power loop. At least one circuit breaker comprises at least one circuit switch corresponding to the at least one drive power loop, and is disposed on the circuit channel with the at least one light emitter diode light source. The at least one circuit channel is controlled by the at least one circuit switch to turn in a state of isolating from a drive power. An ammeter connection line is connected with the two sides one of the at least one light emitter diode light source.