Replaced 4 small flush mount lights over sink. Bought led bulbs. They stay on really dim all the time. Switch won't turn them on or off. Dimmer switch does nothing either

Check the polarity but when reversed they usually do not work at all. Try one somewhere else

Some will do that when they are reversed.Reverse the wires Admin

I see you mentioned a dimmer switch setup. If this dimmer was for your incandescent automotive type bulbs I don't think it will work on LED LIGHTS... LED lights take a different type of DIMMER system to make them work then the Incandescent automotive type bulbs use.Lets hope the reverse wires is the problem but in my case here if the wires were reversed I did not get any LED operations at all...Roy Ken

My guess is that it is the dimmer. Most LED's will not function with this kind of a device in line.

Don't just believe the color code of the wires, incandescent bulbs don't care about the polarity so often the builder didn't care either.

Help! New led lights don't work | Good Sam Community

docj
Explorer
Dec 01, 2015
DC&MC wrote:
Would we be able to use a dimmer from Lowes that says LED compatibles, or are our RV 12v lights diff?

The dimmers at Lowes and HD are for 120V AC circuits. However, there are plenty available for 12V LEDs but you're not going to find many at your local stores. You do have to make sure that the LEDs you are working with are dimmable. Not all are.

You can find some examples of 12V LED dimmers by following this link. I've had multiple dealings with this vendor and have been very pleased. SuperbrightLEDs.com
DC_MC
Explorer III
Nov 30, 2015
Would we be able to use a dimmer from Lowes that says LED compatibles, or are our RV 12v lights diff?
GordonThree
Explorer
Nov 30, 2015
The physics of how an LED operates makes it incompatible with most incandescent dimmers. Even those that do appear to work are only giving you a narrow range of dimming compared to the incandescent bulb that was replaced.

High end RVs that use digital dimmers (the kind with a wireless or wired remote) will dim an LED better, because they're using PWM technology versus a simple rheostat. PWM uses an electronic switch to turn the light on and off really fast, such that it looks like a steady glow to our eyes. The more off than on, the dimmer the light.

Wireless LED dimmers
Ivylog
Explorer III
Nov 29, 2015
I use the same Dimmer as the halogens that I replaced with the cheap China LEDs without any problems.
RoyB
Explorer II
Nov 29, 2015
I've never used one before but there are many listed on GOOGLE SEARCH

LED DIMMERs

Mouse click on the image for more info...

Roy Ken
WyoTraveler
Explorer
Nov 29, 2015
They won't work with a dimmer switch. I have a dimmer switch over my driver position in our MH. LED just glows. I had to remove it. Like a previous post mentions try it in a regular socket somewhere else.
TakingThe5th
Explorer
Nov 29, 2015
DC&MC wrote:
It was the dimmer. We changed it to an on/off switch and it's fine. We can get a dimmer for led's ??

Some LED bulbs are dimmable, others are not. Then there is the switch ...
DC_MC
Explorer III
Nov 29, 2015
It was the dimmer. We changed it to an on/off switch and it's fine. We can get a dimmer for led's ??
2oldman
Explorer II
Nov 29, 2015
dimmer switch
tenbear
Explorer
Nov 29, 2015
Don't just believe the color code of the wires, incandescent bulbs don't care about the polarity so often the builder didn't care either.