Car ran perfectly before.....

Changed:
Harmonic Balancer

Wouldn't start. Cranked but not getting spark to the coils.

Changed:
Crankshaft sensor

Still no start. No spark to the coils.

Checked the battery and all the fuses.

What could be the problem? Harmonic balancer and sensor are aligned properly.

Sounds like a crank shaft position sensor problem. The new one might be defective out of the box, or you may have broken a wire when working on the sensor and the balancer. Sensor mis-alignment could affect performance, but should not result in a no-start.

The Crankshaft Position Sensor connects to the Ignition Module with two intertwined wires. The length of this wiring harness is about 2 feet long and its routing takes it underneath the rear exhaust manifold.

Thanx Guess what.... found the problem.

They sent me the wrong harmonic balancer XD It ate through the new crank sensor we replaced.

Had to be the crank sensor based on your description.