no spark at coil, turns over fine no engine check lite when key is first turned on ,

changed coil,same response. had another exciter coil used but off running truck put it on but same thing, their is power going too both coil and exciter and 12v coming out of primary wire to coil. also changed citcuit opening switch that sits above main computer because it clicks loud when powers turned on and off,same thing happened with new one, so its not that either. curious? if fuel pump goes out is their a safe guard in system that shuts down spark ? thank alot for your time Aloha david