Hey,
I have a 2004 Ford F-150 with 152k miles. 
It’s been slow to crank, then wouldn’t start, just clicking. Jump-started it, and it ran fine. Battery tested good. Took it to my trusted local shop for a tune-up, oil change, spark plugs, and belt replacement ($1400). Two weeks later, same issue. Mechanic replaced spark plug and serpentine belt ($160). 10 days later, same problem. He replaced the starter ($400). Still no luck. Checked the alternator, it’s fine. Now he suggests taking it to a Ford dealership (3-week wait). Could it be the fuel pump or a fuse? It often struggles after being driven, then barely cranks and just clicks. Jump-start works, but once it died at a stop. I’m hesitant to spend more, and my wife is unimpressed. 
Any ideas? 