1977 f100 wont start
replaced cap,rotor,ign module,coil and start solonoid ,battery truck will turn over but not start no spark after trying some troubleshooting i noticed i had no spark when turning key and releasing but if turning key to start and return back to off position ill get a single nice spark so thought it was ign switch just replaced key cylinder and switch still no start i am stumped mind you i am just mechanical but not a mechanic just pickin your brains thanks