Power Antenna

I am new to this fourm. I have a 1997 Miata and the power antenna does not work. I have taken it out and checked the plastic gear line and it is intact. I have power to the antenna and when I pull the fuse and start to replace I hear a clicking noise but the motor will not engage. I can manually pull it up and down and the gear is moving. It has a white box on the side that looks like it might be some kind of relay.

How can I check to see if the motor is good?

Any help would be appreciated.

I did a forum search with no luck.

Chris