At first my air conditoner wouldn’t work, I had the compressor recharged, cooling fan module, alternator, electronic control module((on top of battery)replaced “nothing” Drove it home now won’t start, turn the key nothing no clicking, or engine turn over. All lights work, battery 100% charged, and fuses all good.
What make and model?
If automatic, try to start it in neutral.
If that doesn’t work, check the battery cables, all ground connections and the fat cable to the starter. Put a voltmeter on the thinner cable to the starter and start the car. It should read 12V while starting. IF it doesn’t, your problem could be with the ignition switch or one of the inhibiting switches.
That’s a good start. Report back after trying that.