[Airjer_]

Sounds like you should stop and take a look at the shift cable first. Make sure it is still attached to the linkage on the transmission and better yet make sure it is moving the linkage at the transmission. If its not moving you could replace all the electrical parts you want and never fix the problem.

The range sensor is just under the linkage that the cable attaches to on the transmission. If you look straight down under the master cylinder you'll see it.