OK the thing with the wheels is called the score motor. Several things can start it running but several more things have to be set correctly for it to stop. Since it's not kicking a ball we can assume it's trying to reset.

Are all the score reels set to 0? If not it is likely that that reel needs to be cleaned and adjusted. If this machine has a bonus that unit needs to be reset as well. Finally the player unit needs to be set to the first player and then a ball kicked out.

If you can figure out how set all the reels to 0 and reset the bonus and see if that gets you further. This will also help identify the culprit.

You should read up on ems and their components here to get familiar http://www.pinwiki.com/wiki/index.php?title=EM_Repair

This video is brilliant and will show why it can be hard to get a pinball to reset: