Under my sink is a working duplex electrical socket. My disposal works regardless of which of the two sockets it is plugged in to. The disposal has a grounded (3-prong) plug and this duplex socket is the only thing on that circuit breaker.

My paper shredder (which has a 2-pronged plug) works without hesitation when plugged in to other sockets but does not work at all when plugged in to this socket. The shredder is almost new, but just to be sure I have adjusted the prongs on the shredder's plug to move them to the sides to make sure they make contact with the (brand new) socket. I have tried switching out the duplex socket with a different new socket, I have tried reversing the white and black wires going into the socket, and I have tried working the shredder with the disposal plugged in and with it not plugged in. Again, the shredder will work in every other socket in the room except when plugged in to this particular socket. (Upon further experimentation, no 2-pronged plug devices work when plugged in to this socket.)

I have a multimeter but don't really know how to use it in case anyone needs me to use that to diagnose. What am I missing?

  • Is this curiosity or are you trying to run your paper shredder under the sink? Have you tried to measure the AC voltage between the two prongs of the outlet (which is effectively the black and white wires)? My suspicion is that the neutral is interrupted somewhere (back at the switch, maybe?). Nov 10, 2015 at 5:38
  • 1
    Did you flip the switch? Nov 10, 2015 at 7:57
  • 1
    Try a simple receptacle tester first and see if that sheds any light - one of these things: idealindustries.ca/products/test_measurement/electrical_testers/… Nov 10, 2015 at 11:59
  • It's 2015. A simple search and you can learn to use a multimeter tot test an outlet. Turn dial to V AC (may be marked differently) put the test leads black in common, red in Volts Ohm (Greek letter Omega) ports on the multimeter. Then test outlet inserting black then red leads (in that order) into 1) ground (round hole) then neutral (large slot), should be zero 2) ground then hot (small slot) should be 110-120V, 3) neutral to hot should be a little more than 2 if there's a load on the circuit. Watch video come back post your readings Nov 10, 2015 at 14:44

2 Answers 2


There is nothing wrong with your receptacle.

You just need to switch on the garbage disposal switch whenever you want the receptacle to have power.

Yes, this is how the garbage disposal is controlled. Without this feature, the disposal would run 24x7.


The easiest thing to test with is a receptacle tester:

Ideal Industries receptacle tester

But that won't find all problems, in fact there's a good chance it won't find this one. Never decide you're safe just because a receptacle tester gives you a good indication! Some of the problems they won't identify are dangerous.

Even testing with a meter won't find certain problems. This article:

Outlet Testing Article

details the hows and whys. It shows how a non-contact voltage tester like this one

Santronics non-contact voltage tester

Can spot some dangerous problems that other methods will miss.

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