So I recently had my transmission replaced due to the radiator leak issue, but after it was fixed the car runs but after a while of driving, like half an hour or a bit more, the "PRNDL" disappears from the dashboard, its the only thing that disappears and it takes a bit longer to pick up speed. My mechanic said it was some relay's and had those changed but it didn't fix the problem. Maybe its a sensor or something but I have no idea which one it is or could be or if it maybe is a even bigger problem.
It worked before the tranny was replaced right? That leads me to believe the tech who replaced it is coming up with excuses. Your shift selector should be on the left side of the transmission, and its possible it may have been damaged during removal of your transmission. They wont admit to it im sure, but really, it worked before it went there. However, if its not broken, and its plugged in tightly, then its a wiring issue. I have seen similar complaints, and it was the transmission harness crushed between the tranny, and the engine. Mistakes do happen. However, it needs to be fixed. Keep us updated.