How to install a light dimmer?

I just looked on here and tried to see if I could answer my question but I don't see what I need. I am trying to install a dimmer light switch and there are too many wires. I took off the single light switch and there were two black wires attached, 1 copper ground wire wired to the box and then two white wires capped together and not in use. I purchased a single dimmer and there are two black wires and the green ground wire. I capped the green ground wire as the existing copper wire was already grounded to the box. I left the two white wires capped (since they weren't in use before) and then I attached each black wire to a black wire and it didn't work. So, I changed the black wires to see if that made a difference and it did not. Should I be using one or both of the white wires? This 10 minute project has lasted 30 minutes so far!How to install a light dimmer?Oboy.....



There are so many things going on here, its going to take a few minutes to straighten out...



First... Shut off the breaker to the switch, if you haven't done so.



Be back in a minute....



Ok.... the white wires ARE in use. There are a couple of ways to wire a switch... run power to the switch first.. or to the fixture. it sounds like you have power run to the switch first (actually, thats the way I prefer to do it, myself). The white wires should be twisted together with a wire nut.



Now.... the white wire is the 'neutral' wire... electricity flows thru the black... thru the switch, to the fixture, and back thru the white wire.



On your dimmer switch box, it should tell you what the switch is rated at. By the way.... dimmer switches CANNOT be used with flourescent lights, or CFL bulbs.



The green ground wire from the switch needs to be attached to the gang box, where the bare copper wire is attached. That is.. BOTH .. the green wire from the switch AND the bare copper wire, need to be connected to that box. Just capping off the ground wire from the dimmer switch is NOT SAFE.



Now.. most switches are wired so that the supply comes in one side, and goes out the other. Look at your old switch and it should tell you which way it was set up. Look at the dimmer switch to see which terminal should get the power supply.

Use a multimeter, or tester, to see which wire is the hot wire. To do this, you would pull the wires so that nothing is touching them... then turn the breaker back on. Check the wire by touching a lead to the black wire, and the other lead to the copper wire in the box. BE CAREFUL not to touch any of the wires yourself, while the power is on!



Once you know which is the hot wire, turn the breaker back off, and connect that wire to the appropriate terminal on the dimmer switch. Connect the other black wire to the other terminal.



Some dimmer switches can be turned off, by tapping them, or by sliding the switch to an 'off' position, etc... you didnt specify which type you had.



So.... the dimmer switch didnt work because it was wired wrong, it was turned off, or perhaps youve got a fixture with CFL's, or a flourescent light fixture. In an extremely rare occasion, you get a bad dimmer switch.



I don't think you realize just how dangerous a project this is. You could have easily killed yourself, or burned down the structure. When in doubt call an electrician.



If you make a mistake in plumbing, you get wet.... make a mistake with electricity, and you could die.



BE SAFE

Good Luck



Additional:

Glad to see you've got it working again.

In Seamonster's defense, just looking at your question, as you had it written, one cannot assume you have a basic knowledge of electricity. %26quot;White wires.. not in use%26quot; and %26quot;capped the green ground%26quot; are worrisome statements, hehehe. Never Assume the Obvious. What is obvious to some folks, is not obvious to others... hence your 10 minute project has turned into something larger, hehehe...



I would STILL caution you to attach the green ground wire from the dimmer switch to the ground in the gang box. Do NOT just cap it off.



Good LuckHow to install a light dimmer?it goes in like a regular switchHow to install a light dimmer?click the link..it should help you...good luckHow to install a light dimmer?I am going to be brutally honest here. Stop and call a licensed electrician. If you do not, you are going to burn your house down possibly killing yourself or someone you love, and nullifying your homeowners insurance. there are formulas in place which regulate current and proper switches have to be figured in before even going to store to buy a dimmer. You obviously do not have this knowledge as the way you described your wiring. the two white are capped together as they are part of a circuit that is using that spot as a junction, the ground has to be connected not capped off or you nullify its function and create a fire hazard. you said nothing about metering to identify the hot wire or turning off power at the circuit breaker before working. paying someone for electrical work is a no brainer. How to install a light dimmer?By capping off the ground that is part of the switch and not connecting it to the ground of the box, you leave yourself subject to any fault that ever comes from the switch. Tighten as a rule of thumb 8 turns. Make sure you match the lengths of your stripped wire going into the wirenut.