both wire are white on the cord for my ac unit i need to know how to find the hot wire with my cen-tech p37772 multi meter. I am replacing the plug on the end and cut it without noticing which wire went to the hot.

  • 2
    Are you able to open the unit to inspect where the wires terminate?
    – Hari
    May 1, 2018 at 17:25
  • 3
    Still have the old plug? Are you defeating an in-cord GFCI? May 1, 2018 at 17:51
  • 1
    Is this a 2 wire or 3 wire unit. Is it 120v or 240v most are 120 but more information is needed.
    – Ed Beal
    May 2, 2018 at 16:17

3 Answers 3


You need to pay attention to the comment by @Hari Ganti. The only way I know to make sure you are connecting the right wire to the right place with confidence. Would be to open up and inspect the connection point of the power supply. Then you could ring each wire with your ohmmeter, mark and install them correctly. But if you could get to your connection point, why wouldn't you install a manufacturer approved cord and avoid any complications?


If the cord is one of those flat-type cords with a 90° cord end, then inspect the cord carefully, it's likely that one side of the cord has small ridges that you can use to re-align the cut end with the end of your cord.

Having said that: @Retired Master Electrician is spot on - just replace the entire cord. It'll be cleaner, better, and safer. It's also likely that a replacement cord won't be any more expensive than a replacement end.


For 120 volt equipment, if the load is turned off or not running, then the hot wire is energized and the neutral is not.

Check each wire to ground with the load off. The hot will have voltage and the neutral will have the same potential as the ground.

For 240 volt equipment, both wires are energized at all times.

Good luck!

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