What you describe does not add up, the incoming line should be in one cable, and if so, there would be a dead short the way you said they were connected.

The wires need to be tested individually to see which one carries the line voltage and which one is the grounded one, and where the remaining ones go. You cannot do this with your NC tester, you will need a real tester. There is no way we can figure it out by guessing. If you get a real tester we can help you figure them out.

I am assuming you are GFCI protecting the circuit before installing the grounding type receptacles?

This post was edited by joefixit2 on Mon, Mar 31, 14 at 23:48

>> The outlet was wired with the two black to brass from
>> the one line, and the hot and neutral from the other
>> line connected to the silver of the outlet. I taped them
>> and checked for current and the wire that had both
>> black did not read any current. The other wire did.

Since the single black was hot and it was connected to a silver screw, and the single neutral was also connected to the same screw pair, the neutral should have read as hot. Since it didn't, we're missing some information. Was the thin brass bridge between the two silver screws (or the two brass screws as well) snapped off?

Were the two black wires in one cable? I can't see that. Were they supplied to the box via flex or conduit? Is one wire just wrapped with black tape?

Thanks guys I figured it out. There is a bathroom light switch that feeds from the outlet.

Do not instal grounded 3 prong receptacles in place of 2 prong devices without adding a ground wire or protecting it with a GFCI.