I am trying to hook up a 2 wire lamp to a dimmer switch i am sure i have done this before but i can,t seem to remember how.
There is a red a black and a white i believe, i was told the red does nothing and it should be capped.
Any thoughts on this?
There is a swtch on the lamp which i would like to leave on and just turn it off and on with the dimmer switch which used to work fine with a previous light that was in the place of the one i have now.

 

What sort of dimmer, what sort of lamp?
What are these red/whit/black wires on?

 

Is this a wall switch dimmer? If it has 3 wires (combination of (3) red and blacks) then to use it as a SP dimmer (controlling lamp at switched outlet I'm assuming from one location) you would cap off one of the wires (not the "common" wire). The wire would need to be capped or taped because it would have voltage present when the switch was "OFF".

 

I was told by someone to cap off the red wire.I tried it without the red wire in use at the light connection and the lamp has power when the dimmer switch is off and the switch has no dimming affect on light when the light is turned on at the base of the lamp as there is a rotary type on off switch.
I am stumped as to why it will not dim as the previous light did dim.
Thanks

 

I think I know what your problem is but I'm going to have to make a couple of assumptions. First of all I'm assuming that the "lamp" is actually a "light fixture" that happens to have a switch mounted into it. This fixture is being installed on a ceiling fixture box. The ceiling fixture box has a black, red, and white wire on it and is controlled by a SP dimmer at a One-gang switch box on the wall.

It sounds like the ceiling fixture box may have been set up for a fan / light combination at one time. The black wire was to be connected to the black ceiling fan wire (fan motor) and is unswitched. The fan motor was to be controlled with the pull-chain. The red wire was to be connected to the blue wire in the fan which is for the fan light kit. The red wire would be connected to your wall dimmer switch and the switch would control the light. If you pull the dimmer out of the box you will see the red wire connected to the dimmer. There will also probably be a black wire connected to the dimmer but it is not the same black wire that goes to the ceiling box.

If I am correct, the red wire needs to be connected to your fixture and the black wire needs to be capped off. If I'm not correct, what can I say - I tried.