The outlet tester lie I believed for 8 years

I was doing a service call at a house built in 1982 near Columbus last Tuesday. Plugged in my standard 3-light tester on a GFCI outlet and it read "correct" so I moved on. But the homeowner mentioned her microwave would shut off randomly. I finally broke out my multimeter and found I had a open neutral on that circuit the whole time. That little tester can show a false positive when there's a bootleg ground or something funky. Has anyone else caught a dangerous situation because those cheap testers said everything was fine?

2 comments

2 Comments

adamcoleman12d ago

Read something similar in an electrician forum a few months back. Those plug testers are good for a quick check but can definitely lie to you if there's a bootleg ground or shared neutral.

green.mason12d ago

Tbh I've seen the same thing way too many times. It's wild how a little green light can make someone feel all safe when really the wiring is totally jacked underneath. I had a buddy who trusted one of those testers in his old house and it showed everything fine, but when we opened up a box later we found a bootleg ground that could've fried someone. Honestly those tools are fine for a basic sanity check but they're no substitute for actually knowing what you're looking at.