Problem with electricf motor

I'm working on a spacecraft similar to the Jupiter 2 from the original TV series in the mid-60's. The Jupiter 2 was basically a cool looking flying saucer with a lighted "thing" that rotated on the bottom of the ship. I'm trying to recreate that rotating, lighted "thing", but the motor that I have attached to spacecraft will not rotate. I have plenty of electrical power and an activation group to turn it on. I'm using slider 2 to regulate the speed at which the lighted "thing" rotates. I activate the motor and set the slider to maximum but nothing happens. I have the motor attached to the bottom of the fuel tank that serves as the the bottom portion of the spacecraft. Has anyone else had a similar problem with a motor? On another note, I have "built" a Mars Gravity Probe like the spacecraft that was featured in the first 10 minutes of the movie "Robinson Crusoe on Mars". (Anybody on this forum ever hear of that movie? It's a good one. Made in 1964.) I'll upload it if I can figure out how to upload a craft.