Replaced an outlet and a switch. Switch works but outlet doesn’t. No voltage measured

First thing to check, as @Tester101 points out, is that you've connected the wires to the LINE terminals on the GFCI receptacle. It will also have LOAD terminals, which would go any other outlets you'd want fed from (and protected by) this GFCI. But it doesn't appear that you have any of those.

Next you should carefully use the contact terminals of your multi-meter to measure voltage on the lines:

• If you measure around 120V between the black and white wires leading to the GFCI, and those wires go into the LINE terminals of the receptacle, the receptacle should be test/reset-able and should show 120V when you test between the plug-in slots on the front. If you have 120V at the LINE terminals and not at the front, the receptacle is defective.

• If you don't have 120V between the black and white wires, your circuit is switched off or damaged. You'll need to investigate the wiring to determine what's wrong. Your non-contact tester may have given you a misleading indication; the contact tester is more authoritative here.

• To identify the "true" neutral, measure voltage between an insulated wire and the bare ground wire. Neutral and safety-ground should have zero voltage, because they are bonded in your main electrical panel. So you should have 120V between black and white; 120V between black and ground; and 0V between white and ground. If you have 120V between white & black but 0V on black/ground and 0V on white/ground, then your ground wire is not properly connected.

Finally, you should run a small length of bare wire between the ground bundle in this box and the ground screw on your switch, so that the switch's metal components are grounded.

Two devices in one package can make for twice the confusion

GFCI/switch combinations are a common cause of DIY confusion, as they have more, and more varied, connections than most other electrical devices one can get at the hardware store.

In your case, you have the GFCI portion wired correctly, but the switch is what has you down. It's actually nothing special, just a plain single pole switch with no internal connections whatsoever to the GFCI. However, you seem to have your hots, neutrals, and grounds confused with regards to the switched load. What they mean by "The LOAD must be properly connected to NEUTRAL and grounded." has nothing to do with the wiring in the GFCI box -- in fact, the wiring of the switch to neutral and ground is why the switched load isn't working right now! It simply means that the load itself must be wired correctly and not in a bizarro way (such as across two hots, from hot to ground(eek!), or with a switched neutral). In fact, right now, the load can't work because there's no voltage across it with one end wired to the neutral (and ground) and the other wired back to that same neutral.

To get this all working I would:

• Disconnect the switch-wire going to the white wire bundle from the white wire bundle, and remove the pigtail from the switch/black wire #3 junction to ground.
• Cap off black wire #2 by itself since you don't yet know where it leads. (Sooner or later, you'll find the thing that doesn't work, and then you'll know what that black wire was feeding.)
• Connect one black wire from the switch in with black wire #1 and a black pigtail to the GFCI's LINE HOT terminal.
• And connect the other black wire from the switch to black wire #3.