New to forum need help

I have a 2004 Ram 1500 3.7L. It won’t crank and I have no communication with Ecu. I am not getting the ground from neutral safety switch to make it crank. Getting power from ignition switch to relay when it is in the crank position. I can give it a ground and it cranks but still won’t start with key on. I had power to ecu so I changed it but still nothing. One odd thing is when I turn the key on the square on the park indicator is there for about 10 seconds and then gone on any letter. Thinking of changing the neutral safety switch ext but would that keep me from communicating with ecu? I did the cluster test and have two codes, AA & A6. Any ideas?
Thanks in advance for the help
Update. Discovered range selector switch is internal in the transmission. On the PCM on the black connector pin 29 it should have 12v and does not. Does anyone have an idea where it comes from.

Found the problem. Hope this helps someone else. Pin 29 on black connector at pcm gets power from fuse 23. There is a connection near pcm that separates. There was power there. Pulled other side of red power wire and when pulling out of harness it broke in half. Repaired wire and solved problems.

I'm fairly certain that it is driver's side, before the cat. similar to the pic.

Thanks for the reply.I actually moved my question to the proper forum(hopefully).