Shoutout to the guy who told me to check my ground straps first
I spent three hours last Tuesday chasing a weird intermittent no-start on a 2012 F-150. Fuel pump would prime, starter would crank, but every fifth try it just clicked once. Replaced a perfectly good starter solenoid before I remembered an old mechanic's tip about checking engine to chassis ground straps. Found the main strap corroded nearly through right where it bolted to the frame near the radiator. Cleaned it up with a wire brush, new bolt, and the truck fired right up every time since. Has anyone else chased ghosts for hours only to find it was a simple ground issue?