I have been replacing all of the outlets and light switches in our cottage. Cannot get one GFCI wired properly. There are two black and two white wires with a ground. My tester shows that one black wire is hot. After no success with the GFCI (and a replacement just in case the GFCI itself was defective in some way), I tried just wiring a regular outlet with two and then all four wires, and still no power. Is there anything else that I can check, or have I reached the point where I need an electrician? I can't figure out how I have a hot wire, but still no power?thanks

How did you measure hot. You need a neutral or ground to measure voltage. If you have that you have a circuit. Remember line and load on a GFGI.

How did you measure hot. You need a neutral or ground to measure voltage. If you have that you have a circuit. Remember line and load on a GFGI.
I just used a basic circuit tester. The "hot" wire was the only one that lit up the tester light when I touched it and a ground.
I attached that "hot"wire to the "line" and the other pair to the "load". I finished replacing the other outlets today and noticed that the only other GFCI in the house (which I didn't wire) doesn't work either. Frustrating.

Apparently you are using a no contact voltage sensor. These sense a voltage on a conductor but do not tell you that you have a complete circuit. The symptoms you report indicate that you have a problem with the neutral.

The fact that the other GFI is not working indicates the possibility that it and this GFI are on the same circuit. First try resetting the other GFI. Your work at this GFI, or even at another receptacle, may have tripped it. Purchase a small multimeter and start using it. They are not expensive and give you more information.

Inspect all your work on this circuit looking for a fault in the neutral side. Test the hot for voltage at this and the other GFI using your voltage sensor. Turn off the breaker and again test for voltage with the voltage sensor to confirm that you have the correct breaker and that both GFI are on the same circuit. Assuming that you have no voltage at either, then inspect all other receptacles, switches and lights on this circuit (do work with the breaker off), for a faulty neutral.

If you find that the GFI are not on the same circuit you have a bigger problem with neutrals. That logically should be in the circuit panel which presumably you have not touched and is highly unlikely. Places to look for a fault are outlets on circuits that share a neutral, switched outlets that have a switch loop using the white wire as a hot conductor.

Thanks for the information. I"ll buy a multimeter and start using it when I go back to the cottage. I am unable to reset the other GFCI because the reset button doesn't function. Looks like I've got some scavenger hunting to do.

Thanks for the information. I"ll buy a multimeter and start using it when I go back to the cottage. I am unable to reset the other GFCI because the reset button doesn't function. Looks like I've got some scavenger hunting to do.

Multimeter $5 and GFCI $8 at Harbor Freight.