If I understand correctly, at times there is no response from the starter motor when trying to start the engine. Is that correct? Also, is the ignition switch new?
If it is and since the problem is intermittent, have you checked to see if the starter relay is making a good contract on the fuse box?
Check that first. I attached two pics below. One shows the wiring to the relay and the other shows the location of the relay in the under-hood fuse box.
Remove it and check for any evidence of corrosion or damage to the connectors. If there is no corrosion or evidence, you may want to replace the relay. They aren't expensive. It could be failing internally.
Let me know what you find.
See pics below.
Images (Click to make bigger)
Sunday, April 30th, 2023 AT 8:23 PM