1992 Dodge Spirit No power to my starter

1992 Dodge Spirit 6 cyl Front Wheel Drive Automatic

Everything got power, lights, radio, turn signals, but not the starter, it doesn't click either. Starter itself works, I got it tested. There is 2 wires on the starter, the big red one got power and the little dark one doesn't. Plus the key feels funny when I try to start the engine, it's like if there were no spring anymore. So I got told:
1- Starter relay. (Where is it?)
2- Neutral safety switch.(Where is it?)
3- Ignition switch and cylinder.

And how can I test those guys to know who's the trouble?