I installed a new heater control panel in my 67. The one that was in the car was a not from first gen... long story. There is no wire for the control panel light under the dash. I have the bulb socket but don't know where to wire it to. The one I got has two wires, I know one is a ground but where do I wire the other one into so it works with the rest of the control panel?? Keep in mind I know just enough about wiring to get me in trouble.