[68C15]

I will assume that you have no spark at plugs here. remove the 'tach' wire from cap & use a regular test light to the terminal under cap. what you are looking for is a flashing light as engine is cranked over. if light is steady you have problem under cap (module or pick-up coil). if no light at all you have problem with coil on top of cap (open circuit). hope this helps.
P.S. remove coil cover & look for small metal strap going from one of the coil mounting screws to the middle of 3 wire area on bottom of cap. many times these are left out accidently by someone replacing cap.