Yes...6 volts on 'E' side terminal and sender on 'F' side terminal. Gauge must be grounded through the case in the dash assembly and the sender must be grounded to the system through intimate contact OR a wire from a mounting screw to the body/tank/frame.
If 12 volts was connected to the gauge at some point, there is some chance it was destroyed. This is not a 'for sure'! Folks do evidently run the gauges on a full 12 volts without killing them, but as you have discovered, they do make a voltage reducer intended just for this application.
Remember, grounding is important. That is what makes this system function...or not function. Good luck!
Stuart
