Cannot hear or feel the transmission engaging

These are most likely going to be two different issues unless something was missed when putting the transmission back in.

However, let's address the transmission issue first. If this was not an issue prior to replacing the torque converter, then the likely issue is that the fluid is low, or we have an issue with the converter.

https://www.2carpros.com/articles/how-to-check-and-add-transmission-fluid

If the fluid is at the correct level, then the likely cause of this is the converter is not fully seated causing the pressure not to build to allow the vehicle to engage.

Below is a process on how to check the line pressure which should confirm this is the issue.

Let's run through this info and go from there.

Thanks

Thanks for the update. That is great that you figured out what was going on.

If you need help with the battery issue, let's get a new post started on that and we will jump in on it and see what we can figure out.

Thanks