S-10 won't start intermitantly

You have to test when the problem is ongoing. If the problem is on a wiring circuit somewhere, replacing the part won't fix it.

In the diagram at starter relay, terminal 30 is hot all the time. Terminal 85 goes hot with key in the crank position. When the relay is energized, that arm with the arrowhead moves to terminal 87 and that terminal becomes hot, carries voltage to starter solenoid.