I assume it is not an induction type light with a big loop for the plug wire? Hook up the red and black leads to the battery. The third lead is for the spark and you have to insert the coil spring at spark plug #1 between the wire and the plug and clamp this lead to it. Do not melt it on the exhaust manifold. Start theCheck that out carefully, I hope I remember it right. car and aim the light at the timing mark. You should take a good look at that little graphic to make sure you read the 2l0 as 20 degrees BTDC, and 1l0 as 10 degrees ATDC etc. There will be a mark but no number at TDC so you have to figure out where 12 degrees BTDC is and align that with the pulley timing mark by rotating the distributor (which has a single 12 0r 13 mm lock nut to loosen when you start this procedure). Try not to turn the distributor unless the car is running and keep it running as you adjust. It is also helpful to operate at the correct RPMs. And disconnect the vacum advance before timing, although I rarely remember to do that. Once timed the B230 or B221 hardly ever slip.