Does the starter have 12 volts on both terminals with the key in the crank position when its not starting?
WOuld you like a wiring diagram?
WHat is the year make and model?
Auto or manual trans?
Make sure the relay has two powers with the key on and that it is getting grounded by the control module. HEre is a wiring diagram. THe other pictures help identify the components on the diagram.
SUre... you bet!
I will be able to diagnose this problem if you stick with me.
This will take some elbow grease on your part.
DO you want to continue?
Ok... do you know where the starter relay is?
Can you get to the wires that go into the back of this relay?
TELL ME WHAT COLOR THE FOUR WIRES ARE!
ALso, Turn the key on and see which ones have power to them!
DO THIS WITH THE RELAY OUT!