[MT-V6]

Which motor in the seat isn't working?

 

[MT-V6]

I doubt it is the motors as there are lots of them, unlikely they all have an issue

Either power to the seat, or maybe the button pack

Would recommend checking to see if you have 12 volts on the power connector. Without being able to move the seat it might be tricky, but can you access the plastic panel under the seat on the carpet?

You want the big red connector, only 2 wires. See photos here Retrofit: Electrically Adjustable Seats