At some point there should have been 2 positive wires, one on each side of the ballast. One would have been hot when the starter was spinning and the other while the key was on. Whoever removed the ballast may tied some wiring together elsewhere. I would double check the black/White from the harness and make sure you getting power with the starter is cranking. If not check the brown with red crimp.

Do you have a factory tach or aftermarket?

If it is a factory tach I would assume the smaller wire from the harness goes to the tach.

The brown wire with the red crimp has me stumped. Where does it run to?