The black of the timing light is connected to the negative pole of the 12 volt electronic. Timing, etc., the red test clip is between the positive pole of the 12 volt battery. 1X Automotive Timing Light tool (with Colour box ).
Automotive tool Inductive Ignition Stroke Petrol Engine Car Digital Timing LigZE
Digital Timing Light Automotive tool Inductive Ignition Stroke Petrol Engine Cwk
Automotive tool Inductive Ignition Stroke Petrol Engine Car Digital Timing Light
