Overhead light in attic stopped working - not the bulb. Checking with multimeter set to ohms, between black & white terminals, display shows a 1 and the light comes on, Switch position doesn't change anything - this happens with the switch in both on and off positions.
Reading voltage - black to white starts at 120V, then decreases to about 94V within 5 or 6 seconds. Black to ground shows 120V, white to ground shows 0V. Switch positioned either on or off doesn't change the voltages.
I assume the switch is bad, but I am not an electrician by any measure. Has anybody ever seen something like this before?

  • display shows a 1 and the light comes on ... what does that indicate? ... why don't you just say how many ohms you measured?
    – jsotola
    May 31, 2023 at 0:23
  • 4
    wait a minute! ... did you measure resistance of a live circuit?
    – jsotola
    May 31, 2023 at 0:30
  • 1
    @ Rob Harrison, You probably completed the circuit when you switched to ohms. The switch is bad.
    – RMDman
    May 31, 2023 at 0:44
  • 4
    And the meter may also be, now.
    – Ecnerwal
    May 31, 2023 at 0:51
  • 2
    light over my head came on ... I thought that you were talking about a light on the meter
    – jsotola
    May 31, 2023 at 1:20

1 Answer 1


There should be no voltage drop unless loose wire.

The Ohm reading is ONLY for measuring continuity/resistance when all the wires are disconnected. It can not be used on Live wires. It uses small internal battery to send small voltage and current to the loop and reports results. If it shows Infinite, means the circuit is Brocken. If it shows zero, the circuit has no resistance in the path.

Depending on your multimeter type it might have protected it self from you connecting it to 120 Volt wire, or it might have died.

To test the switch, DISCONNECT the wires. Now use multimeter in Ohm position, and observe, showing infinite in switch of position and showing zero in the on position.


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