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First off ---- I am by no means an electrician.

That said, I have a dimmer switch that needs to go..and be replaced by a new one. However, upon searching the internet and reading the instructions several times over, I am stuck. The dimmer being replaced is from 1978 (original to the house). I have attached photos of the new one, the old one (still attached the house) and the instructions. All the help they have been was saying, "consult an electrician if what is on the wall doesn't match the paper..."

Please note that the wires attached to the switch are all black, they just have over-spray from painting on them. Additionally, there is a ground in the back but I don't know which is the positive or which is the negative.

I appreciate any and all help! I can easily provide more pictures if needed or information.

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J Crosby
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2 Answers2

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You have a "single-pole" arrangement, i.e. one switch controlling the load (the light). You simply need to turn off the circuit breaker controlling this circuit, remove the two wires from your existing dimmer switch and place them on the two wire terminals on the new dimmer switch (the terminals that are NOT green). It does not matter which wire goes to which terminal.

There does appear to be a ground wire (bare) under a screw in the back of the box; if possible you should attach a short green or bare wire from the green terminal on the new dimmer to that same screw (or alternate ground screw) in the back of the box. This is not required for the new switch to work; it is a safety feature.

Attach the dimmer and cover plate to the box, then turn the circuit breaker on. Done.

Jimmy Fix-it
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Based on the instructions and Single Pole installation (i.e., one switch rather than 2 switches), this should be quite simple:

Line - Hot

This is one of your black wires. Hard to tell from the old dimmer *and it may not have made any difference on the old dimmer which wire was hot and which wire was switched hot. It might not matter on the dimmer, but you would have to read the rest of the instructions to figure that out. If it does matter, you can tell by turning the old dimmer off and then checking with a non-contact tester. Whichever wire lights up is hot and the other is switched hot.

Neutral

The installation instructions mention neutral but don't actually use it. So you can ignore that. As it turns out, you do appear to have neutral (the whites all together), which matches the diagram, but it actually doesn't matter in this particular case.

Ground

If you don't have any ground wires then you can, provided everything else was done right (ha ha ha!), ground to the metal box using a ground screw with a pigtail like. However, with switches (as I understand it, for some reason, not with receptacles), you can ground from the metal switch yoke to a metal box by simply screwing it in place, provided there is no paint on the box or paper spacer on the screws or anything else that would prevent a solid, electrically conductive, connection.

Load - Switched Hot

This is the "other" black wire.

As far as "all black": Hot, switched hot and traveler (for 3-way switches) can be any colors except: White (allowed in certain situations), Gray, Green or bare wire. Black + White is the most common type of cable, so "all black" is typical, albeit confusing. But even if the colors were Blue & Red, that wouldn't actually be any more informative.

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