There’s a smaller wire on the starter (often with a plastic connector). That’s the signal wire. It tells the starter, “Hey, wake up and spin.”
Touch your red probe to that small wire’s terminal, black to ground again. Now have your friend turn the key. You should see 12 volts here too, but only while the key is held in “start.”
If no voltage appears here, your ignition switch or safety switch (like a clutch or neutral safety switch) is the real villain. The starter is innocent—set it free.
