I recently installed a rebuilt torque converter in a friend's 2004 RR HSE with BMW transmission. Im a full time mechanic but I've dealt with 2 RR's in my career. Transmission removal, torque converter swap, and transmission replacement went fine. No issues at all. Went to start it and battery was dead. Put it on charge over night. Next morning put fully charged battery back in. Went to start it. Key turned fine but wouldn't crank. Dash lit up. Had full battery power. Just no crank. So I started simple. Found no power to the starter relay behind the battery. I jumped 12 volts to the relay with key on and it started right up. So I was thinking alarm problem. Since it was running I went ahead and topped off the transmission fluid at temp. Went to drive it and it wouldn't shift gears at all. Info center said trans failsafe program. Checked codes got P0705 neutral safety switch. Checked the switch out thoroughly with info from this forum. It checked out in all gears. Checked good also at the connector to the transmission control under the hood. The owner even found a used one for a decent price and thought we would just try it. No change. Code would come back and it stayed in failsafe. And it still will not start with the key either. I'm at a loss. I don't think the trans failsafe is causing the no start issue but could the fact that I'm jumping it to the relay to start it possibly be causing the trans failsafe by not communicating with the neutral safety switch? Why do I keep getting the pO705 when the switch is good? I'm very stubborn and it isn't easy for me to admit defeat. I don't want to take it to a dealer if this is something I can fix without any RR specific software or diagnostic equipment. So if anybody could help a brother out with any kind of idea I would greatly appreciate it. My ideas are running thin. Thanks for reading and sorry for the book I wrote. I just want to be specific as possible.