Starter relay amperage

Okay, you have something in the harness that making the connection intermittently.

I attached a diagram for you.

Check the relay for power when it does not start. I am wondering if you are losing power to the control sod when it does not start from the ignition switch.

https://www.2carpros.com/articles/how-to-check-wiring

https://www.2carpros.com/articles/how-to-check-an-electrical-relay-and-wiring-control-circuit

Roy.