all the positive connections are on a common buss meaning that if yo touch a meter to the coresponding pin of any connection you will have continuity. the same can be said for the negative buss in the receiver. the servos and the reciever draw their operating power from these busses and hence forth as long as you plug the battery in correctly to the reciever you will be able to use any open connection. If you have no open connection you will need a y connector to supply power to the busses. conectors are three pin, positive negative and signal for servos and just positive and negative for batteries