Entire Circuit: Hot-Neutral 90v

[oguruma121]

Short Version: Single circuit in the house doesn't work. I cannot find a working receptacle. I'm pretty sure I found the "first" receptacle in the circuit. Wires in that receptacle test hot:neutral 90v and hot:ground 120V. No continuity at the panel from hot:neutral, leaving me to believe the problem is the romex itself or a junction somewhere I cannot find.

Long version:

Son noticed no power in his room.

15-year-old double-wide mobile home. No "modifications" made recently (no holes punched in the walls to nick some romex, and no electrical modifications made.

115v circuit for 2 bedrooms. About 10 receptacles on the circuit, 2 overhead lights, and two half-switched receptacles.

I get 120v hot to ground, but only 90v from hot-neutral. This is the same on every receptacle on the circuit. Only this circuit is affected. All measurements were taken with a Klein clamp/mm and double-checked with a cheapo Walmart meter. I get 120v hot:neutral and 120v hot:ground on the other circuits.

I figured I would try to find the first "good" receptacle, and start there. The problem is that there isn't a "good receptacle." They all only have 90v hot:neutral.

I found a receptacle that has 3 pieces of romex in the box. I separated those pieces of romex out from the receptacle and wirenutted the wires. I turned the power back on and none of the other receptacles on the circuit were hot at all anymore. A piece of romex in the aforementioned box was still hot, and it tested at 90v hot:neutral.

I turned the power off and spliced that piece of wire black:white. Inside the panel, I could not get continuity on those wires. I COULD get continuity when splicing black:green, though.

I'm assuming based on all of the above that the open neutral is between the panel and the end of that romex. Now, because nothing else had power on that circuit, that run of romex either goes directly to that box, or there is a junction under the house that I cannot find.

My logic now is that the best thing to do is just run a new piece of romex/MC into that box.

 

[AC Power]

From what I am understanding, you are correct. The neutral's connection is compromised somewhere between the panel and the firstmost receptacle in the circuit.

Ensure the neutral connection in the panel is tight, and the neutral connections at the firstmost receptacle is good/tight too. If it still reads 90vac for hot to neutral, then you may need to follow the cable run (it possibly runs along the support beams/timbers under the trailer/s). If you find a junction box under the trailer, that is likely where the problem might be. If you find a junction box under there, redo the splices in it, then check your bedroom circuit again. If that was the culprit, redo ALL the connections in the "under-trailer" junction box as they too would be suffering from corrosion and/or humidity/dust/airborne dirt.

Let me know what happens.

Thanks