I ordered a 115 volt primary, 12 volt secondary transformer. I received it and this is my problem: Has 2 wires for primary got that, has 2 red wires and one white wire on the secondary. When I connect to 115v and check the secondary Ground to white and check each red wire I have 7.5 volts out of each read wire. I need 12 volts, am I missing something? Why does it have 2 red wires? How do I get the 12 volts I need?