Hello and welcome to 2CarPros. I understand you replace the starter motor and still clicks? First thing you need to check is your battery. If battery is good, verify the cables are clean and free of corrosion. Also I need you to measure the voltage at the big red wire at the starter. You need to have battery voltage. If low voltage or none then there is an issue somewhere in that battery cable.
If you have battery voltage at the cable with an assistant, remove the trigger wire at the solenoid and with a volt meter check for battery voltage when the assistant turns the key to the crank position on the key. If battery voltage is present then check your ground cable as well. If you have high resistance at the ground it will cause a starting issue. If all is good then try turning the engine over by hand to verify the engine has not seized.
Here is a link on starter operation:
https://www.2carpros.com/articles/how-a-starter-and-solenoid-works
Here is link on volt meter usage:
https://www.2carpros.com/articles/how-to-use-a-voltmeter
And another link on how electrical systems work:
https://www.2carpros.com/articles/how-a-car-electrical-system-works
Let us know the voltage measurements and we can proceed from there.
Friday, August 23rd, 2019 AT 9:21 PM