Took me 3 weeks to track down a bad neutral in a strip mall panel in Dayton
Kept chasing voltage drop on one circuit and swapping breakers before I finally found a loose neutral on a shared bar behind the drywall. If you've dealt with shared neutrals in older retail spaces, how do you usually trace them without opening every wall?
How did you finally narrow it down to that shared bar anyway? I feel your pain on this one, I spent almost two weeks in an old strip center chasing the same kind of ghost. Kept reading 96 volts on one leg and it made no sense until I popped a few cover plates and saw somebody had landed two circuits on one neutral way back when the place was built. What worked for me was killing one circuit at a time and watching the other one's voltage jump, that told me who was sharing. Then I used a tone tracer from the panel to follow the wire through the ceiling so I didn't have to rip open every wall. Still had to cut one small hole but way less than tearing the whole place apart. Those old retail builds are the worst for this because nobody ever labeled anything right.