[pumpkin321]

A junction box has 3 wires, a hot, one running to a porch light, and another feeding 4 l.e.d. lights. It uses a stacked single pole switch which was changed out last week. At first everything worked well, but now it's not. At first I thought it was the switch, so I used one single pole switch on each line (porch and l.e.d.) individually. This is what is happening. When l.e.d. circuit is switched on only 3 out 4 lights come on. And when patio switch is on patio does not turn on (bulb is good) and all 4 of the l.e.d. lights come on but are very dim. Please help.

 

[joed]

Look for an open neutral. since you have worked in the switch box I would start there.

 

[pumpkin321]

There is no neutral in the box. But I could look for one at nearby boxes or outlets. What do I look for though when testing? What are symptoms of an open neutral? Thank You.

 

[Fosti]

If there is no neutral then you have no return to the panel box. You have a floating ground which is dangerous to say the least. You need to rerun that wire so you have the required neutral. It sounds as though the ground is being supplied by possibly metal buy not electrically connected.Be careful, don't try to just add a neutral, replace the wire so that the wire carries a black,white and ground conductor in the same jacket or conduit if it is conduit that you are using.

 

[TimPa]

tell us again what wires are in the box. be specific.

so there were 2 switches controlling the lights initially, and they all worked properly?

 

[pumpkin321]

3 wires are in the box. 1 is hot (120v from wire to metal box), one other goes to a patio light, and the third powers 4 l.e.d. lights. And yes a double stacked switch worked fine and now it doesn't.
Today, I removed light bulb from patio light fixture and 4 l.ed. lights don't go dim anymore (when patio light switch is on and l.e.d. switch is off). Also, patio light neutral wire shows 120 volts when switch to l.e.d. is on and switch to patio light is off. One last thing, still only 3 out of 4 l.e.d lights work.
Thank you for all your helpl

 

[joed]

You need to track the circuit and see where the cables go. I think you have an open or loose neutral in one of the junctions somewhere common to both lights. It could be in one of the fixture boxes.
I would try to find the box feeding the switch box. That would be one place where the neutral from both circuits comes together.

 

[MrElectricianTV]

3 wires are in the box. 1 is hot (120v from wire to metal box), one other goes to a patio light, and the third powers 4 l.e.d. lights. And yes a double stacked switch worked fine and now it doesn't.
Today, I removed light bulb from patio light fixture and 4 l.ed. lights don't go dim anymore (when patio light switch is on and l.e.d. switch is off). Also, patio light neutral wire shows 120 volts when switch to l.e.d. is on and switch to patio light is off. One last thing, still only 3 out of 4 l.e.d lights work.
Thank you for all your helpl

When you say double stacked switch, are you referring to a combination device that has two single pole switches on one strap?

If so, you probably wired it wrong. The hot connects to the side with the common link between the switches. The switch legs each connect to the separate load side of each switch.

Can you post a picture?

 

[pumpkin321]

Yes, I am referring to a combination device that has two single pole switches. Device is wired correctly, I know this because I wired it wrong the first time (when I wired it wrong, one switch would turn both sets of fixtured on and off and the other switch would do nothing). By the way, I tried to dublicate this incorrect wiring but it did not have the same effect (porch light would not come on). I believe porch light is now "bad" because you have 120v to it, bulb is good, and there are burnt marks inside. I removed the bad fixture, and as I stated earlier, 4 L.e.d. lights don't dim anymore, in fact, this happened by just removing the bulb. Why am I getting 120v from neutral to ground (metal box) at the porch wiring? Thank You.

 

[joed]

Why am I getting 120v from neutral to ground (metal box) at the porch wiring?

For the third time it is because you have an open neutral somewhere.