Please explain to me how a sunroof harness wiring will cut your car off after the car has been started and you change gears .

I don't have the faintest idea...Google it U can Google anything!🤣

I don't know anything about cars. I drive cars, I don't fix or work on cars. I wish I could.

That would be plausible, the sunroof harness has a relay. If there is a cut wire or a power surge the car will immediately cut off to prevent any harm. But for that we will need to proceed to do a Diagnosis on said issue, just to be on the safe side. I hope this gives you an idea. You are more than welcome to bring your vehicle in for a check up. No appointment necessary.