Not sure about a control module. The socket should be positive and negative. Turn your lights on and put the meter test leads in the socket first. If you get a reading and it has a minus in front of it, that just means you have the plus and minus flipped but you are getting voltage at the socket. If you aren't getting anything, use a good ground for the meter negative lead and then probe each socket lead again to see if you get anything. If you get a reading on one then I would think there is a problem with the socket ground. If you get no reading on any of the socket leads, there is no power going to that socket. At that point you might want to request someone to post the circuit diagram to help you out further. Let us know what you find.