Center brake light

Thank you, I'm going to try running a separate ground wire. I'll reply in a couple of days.

Problem solved. Using a multi meter to measure voltage can give misleading readings because the meter does NOT apply a load to the circuit. When I used a test light to measure the voltage at the light socket, I did not have any power at the light. A friend of mine who is an electrician told me the proper way to measure voltage is with a test light because it applies a load to the circuit. Using the wiring diagram from Ken, my friend noticed that the light switch has two contacts, one for normal brake lights and one for the center light. He snapped the switch several times and contact was made to the center light. All is well that ends well. Light now functioning correctly. Thanks for the help.