Old Bathroom wiring(1set) to GFCI/Outlet combo?

Question

I have an older house where the bathroom had one switch that controlled an overhead light. The wall has only one Positive and One negative(no ground.) I bought a GFCI switch/outlet combo, where the switch part had wires integrated into the unit itself. I assumed that this was for my type of wiring, the integrated wires go in one set of holes in the back the wall wires the other. When installed, the switch worked, but not the outlet.. Should this have worked? Is it just possible that the outlet is defective.

I've uninstalled the outlet and the reset / test button does nothing.

Thanks to anyone that can help,

RG

Answer 1

Old systems did not have a green or bare exposed wire protruding from the box, but there was a common ground wire attached to the metal box.  Your GFCI (Ground Fault Circuit Interrupter will not work if it cannot detect a ground fault.  You must attach the ground wire to the box.  

Wire it up again with the unit grounded and test again.

Depending on the source of power, the outlet may work only when the switch is on.  If the power comes into the ceiling light fixture, the lines comming into the switch box are breaking one leg only, which should be the hot (black) wire.  The white wire in this case is a continuation of the black wire back to the light fixture.