How do I check my negative battery terminal to make sure that’s what the cause of my car not starting is?
Make sure its tight.
Make sure the terminal is tight to the battery first. If that doesn’t solve the problem then;
Using an Ohm meter, check the resistance between the negative battery terminal and a clean spot of bare metal on the engine. It should be essentially zero.
I would like to know more about why you’re asking.
Are you having starting issues? Who told you the negative battery terminal was the issue?
Just be sure all corrosion is removed from the battery post and the cable clamp.
There is a special brush that you can buy at any parts store , that is made for this.
Then tighten it just so it’s snug and can’t move.
Do the same with the positive terminal also.