Only getting 65VAC at switch and at light fixture

[Uncle Ben]

Hey everyone, I replaced a light fixture on a small/finished out-building's porch light that never worked since we bought our property. I assumed the fixture was bad, and we wanted a nicer-looking fixture anyway, but after replacing the light fixture and putting a new bulb in it, the new fixture did not work either. I tried another bulb, then started checking the voltage, first at the fixture, which was showing only about 65 volts. I went ahead and swapped out the switch, since I figured that would be a potential quick & easy fix, but that didn't fix it, and I am showing the same 65V at the switch as well. When I put my multimeter probes on the hot and ground wire of the switch (instead of on the hot and neutral), I get 120V.

I opened up the electrical panel to see if there was anything fishy there. The only thing I found was that there were two neutral wires that were connected to the ground bar, so I switched those over to the neutral bar. I didn't necessarily think that would fix anything (which it didn't), but I figured I might as well correct that to make the connections proper. There was also a double-tapped neutral that I corrected as well.

Anyway, since I'm not seeing anything in the panel or in the switch box that looks incorrect, what else should I look for to correct this type of voltage issue?
Thanks in advance for your input!

 

[The Cobbler]

bad neutral somewhere

 

[wyliesdiesels]

got a poor neutral connection at a splice somewhere...

 

[inphx]

or... two lamps miswired in series 50% + 50%? did you measure with the bulb in or open circuit no current?

 

[justsam]

What else is on this branch circuit? Can you logically work back from this location and see where you may have a loose neutral splice or back stabbed device?

 

[Chuckster in NJ]

Sounds like a series circuit…….. Start unscrewing bulbs and unplugging receptacles and see what happens.

 

[OccupantRJ]

Look for a nail driven through the wire at some point. I once found 70 volts on a wire in this situation.

 

[Uncle Ben]

or... two lamps miswired in series 50% + 50%? did you measure with the bulb in or open circuit no current?

There are two separate lights/switches on this circuit. There is the outside "porch light" that is getting only 65V and not functioning, and one ceiling fan/light that is working properly.

When checking the "porch light", I checked the voltage at the wire ends without the porch light fixture connected, and also checked the voltage inside the bulb socket of the light fixture, which was 65V in both cases.

When checking the voltage at the switch, I think there was no bulb in the fixture most of the time, but I think I did check voltage with a bulb in as well, though not really intentionally. If checking the voltage at the switch without a bulb in the fixture would help point to a specific type of issue, then I could check it again without a bulb to be sure.

 

[Uncle Ben]

What else is on this branch circuit? Can you logically work back from this location and see where you may have a loose neutral splice or back stabbed device?

There are two separate lights/switches on this circuit. There is the outside "porch light" that is getting only 65V and not functioning, and one ceiling fan/light that is working properly.

The only problem with working my way back along the circuit is that the interior walls are all painted plywood (it's a finished "shed" building), so I would have to remove the trim and wall boards to get to the wiring to find a bad splice...but if there is a nail or screw going into the wall board that could be stabbing a wire, then I suppose I could start removing nails or screws where something is attached or hung on the wall to see if that eliminates the problem.

 

[OccupantRJ]

I have not tried this, but I wonder if a non contact voltage detector would find that nail or screw?

 

[BrandonV]

I have not tried this, but I wonder if a non contact voltage detector would find that nail or screw?

If the nail or screw made contact with the hot wire, yes.

 

[justsam]

In your original post you stated you had 120VAC at the switch location, if you were on hot and ground, but 65VAC if you were on hot and neutral. What do you have at the light location measuring between hot and ground and hot and neutral?

 

[sparky 1971]

Are both switches on the same circuit and if so, are the neutrals spliced in the switch box. If that is the case, break the joint on the neutrals, cut the ends off the wire and make a new splice.

 

[justsam]

Is the wiring at the switch location just a switch leg, and the white wire you are seeing is not a neutral, but part of the switch leg? This would explain why you see 120VAC hot to ground, but not hot to white wire.

 

[Uncle Ben]

In your original post you stated you had 120VAC at the switch location, if you were on hot and ground, but 65VAC if you were on hot and neutral. What do you have at the light location measuring between hot and ground and hot and neutral?

At the light fixture location I have 65VAC between hot and neutral, but I did not think to check between hot and ground at the light location. I can check that later.

 

[wyliesdiesels]

can you post some pics of the wiring inside the switch junction box

 

[Uncle Ben]

can you post some pics of the wiring inside the switch junction box

Yes, I can definitely do that. I'll try to get some pictures soon. Thanks everyone for your input so far!

 

[inphx]

Should we do a wellness check? Just curious what you found.

 

[Uncle Ben]

So nice of you to follow up! (this forum is the best!!!)
Unfortunately, there are too many other projects and to-do's going on, so this has gone on the back burner.