I have an 06 Monte Carlo with 180,000 miles. Had to just replace the whole shift linkage and the transmission cable that runs to it. We get that taken care of and now the car won’t go into the off position. It starts and runs fine, everything works fine. The steering wheel isn’t disengaging when I try to turn it off though. It did this a few times before and I would play with it and eventually get it to work right. It’s very annoying because I’m going to have to unplug the battery post every night and plug it back, and it’s a new battery. Any idea how to get this car to turn off completely?

 

I have seen this before. Remove the ignition switch and check the the condition of the transmission shift cable. The switch itself might have an open contact internally.

 

I have had that problem with my ‘04 MC.... I had to remove the center console, I then found a cable that was sticking. Once I fixed that, the problem went away.