Simple fuse box fix?

Before you buy a starter relay check it out.

The brown wire is supposed to ground that relay terminal in park or neutral

The yellow is 12V from the key in the start position. Those two are the magnet/ coil of the relay

So "rig" a test lamp to the yellow, twist the key to start. You should have voltagle

"rig" the light to the brown connection. Do this with all wiring connected normal. If you get a light, the neutral safety switch is NOT GROUNDING

Hold the key to "start" and move the shifter from park to neutral and back. If it tries to engage or clicks, you are "in the area." Either the switch is bad, or the linkage is out of adjustment

You can also remove the brown wire, hook an alligator lead to that relay terminal, and ground it. Using the key, it should crank, be SURE it is not in gear

If the yellow is getting voltage (crank) but the relay won't engage, time to replace the relay