Do a search and I'm sure you'll find some very useful info. I don't have a roadster but from what I've read about top malfunctions it could be a couple things. It could be the switch in the trunk. You know where you hook the partition in the trunk and latch both sides. If it's not seated correctly, it may not recognize that the partition is in the correct position and hence not operate. It also could be a bad switch, even if it is seated correctly. I think only one side has the sensor ........ I believe it's the left side latch.

It could be other things as well but that seems to be a more common issue.

Good Luck.