You turn the ignition key to start and nothing. All I hear is a click. Batteries are almost new and charged up. All I can think of is the small switch
or breaker pops up but it is closed and appears to be ok. The solenoid seems ok and connections are tight. Battery connections are tight. I wonder if the breaker switch is faulty.
Bad ground to ignition switch/button or the solenoid.
Use a remote starter switch or a screwdriver to jump the terminals on the starter to confirm. Then start tracing wires and cleaning the low amperage connections.