Forum Discussion

tommymsw's avatar
tommymsw
Explorer
Feb 26, 2018

Dimmer wall switch for interior LED lights?

I just switched my old tube florescent lights out with dim-able LED strips. I bought a DC dimmer wall switch for the lights but it had 4 wires and there was no way to install into my 2 wire system.

I can find nothing on the internet. Has anybody put a dimmer switch in a 2 wire RV system?
  • Gdetrailer wrote:
    ScottG wrote:
    Gdetrailer wrote:
    ScottG wrote:
    There are a bunch of them on eBay. Just search for RV led dimmer.


    2 Wires?

    Not so sure about that unless they are nothing more than a variable resistor.

    DC electronics will need at least THREE WIRES in order to work.

    Input + from battery

    Battery "ground" (-)

    Output + (variable 12V DC) to lights

    Since OP has only 2 wires to work with they will most likely have to run a battery "ground" (-) to the switch location.

    I suspect that the OPs wiring is only Battery + and the switched + that returns to the light fixture and no battery (-) to be had...


    They're not just pots and they don't need three wires if they have full 12v coming in because they use that to power an appropriate circuit.

    Here are examples:
    Simple surface mount
    Wall mount led dimmer

    I have both of these.


    OP said they only have TWO wires.

    That means they do not have 12V NEGATIVE GROUND where their switch is.

    The item you selected NEEDS the 12V NEGATIVE GROUND in order to work.



    Please note, the two terminals marked (V-) in the picture from your link. Those ARE for the 12V NEGATIVE GROUND CONNECTION.

    That device WILL NOT WORK without a connection from the 12V NEGATIVE GROUND.

    The OP WILL have to run a separate 12V NEGATIVE GROUND to make that or any other dimmer work.

    This can be tricky to impossible in a typical trailer wall to fish wires.


    I've run wires throughout RV's countless times. Rarely has it ever been impossible to do what was needed.

    OP let us know the specifics of your situation. Most likely it can be done. I would start buy pulling the existing switch and looking behind it. You may find more wires buried deep.
  • ScottG wrote:
    Gdetrailer wrote:
    ScottG wrote:
    There are a bunch of them on eBay. Just search for RV led dimmer.


    2 Wires?

    Not so sure about that unless they are nothing more than a variable resistor.

    DC electronics will need at least THREE WIRES in order to work.

    Input + from battery

    Battery "ground" (-)

    Output + (variable 12V DC) to lights

    Since OP has only 2 wires to work with they will most likely have to run a battery "ground" (-) to the switch location.

    I suspect that the OPs wiring is only Battery + and the switched + that returns to the light fixture and no battery (-) to be had...


    They're not just pots and they don't need three wires if they have full 12v coming in because they use that to power an appropriate circuit.

    Here are examples:
    Simple surface mount
    Wall mount led dimmer

    I have both of these.


    OP said they only have TWO wires.

    That means they do not have 12V NEGATIVE GROUND where their switch is.

    The item you selected NEEDS the 12V NEGATIVE GROUND in order to work.



    Please note, the two terminals marked (V-) in the picture from your link. Those ARE for the 12V NEGATIVE GROUND CONNECTION.

    That device WILL NOT WORK without a connection from the 12V NEGATIVE GROUND.

    The OP WILL have to run a separate 12V NEGATIVE GROUND to make that or any other dimmer work.

    This can be tricky to impossible in a typical trailer wall to fish wires.
  • Gdetrailer wrote:
    ScottG wrote:
    There are a bunch of them on eBay. Just search for RV led dimmer.


    2 Wires?

    Not so sure about that unless they are nothing more than a variable resistor.

    DC electronics will need at least THREE WIRES in order to work.

    Input + from battery

    Battery "ground" (-)

    Output + (variable 12V DC) to lights

    Since OP has only 2 wires to work with they will most likely have to run a battery "ground" (-) to the switch location.

    I suspect that the OPs wiring is only Battery + and the switched + that returns to the light fixture and no battery (-) to be had...


    They're not just pots and they don't need three wires if they have full 12v coming in because they use that to power an appropriate circuit.

    Here are examples:
    Simple surface mount
    Wall mount led dimmer

    I have both of these.
  • 4x4van's avatar
    4x4van
    Explorer III
    Just google "12vdc led dimmer". Dozens available, Amazon, eBay, etc.

    As Gdetrailer says, OP will likely need to run a ground wire to the switch location.
  • ScottG wrote:
    There are a bunch of them on eBay. Just search for RV led dimmer.


    2 Wires?

    Not so sure about that unless they are nothing more than a variable resistor.

    DC electronics will need at least THREE WIRES in order to work.

    Input + from battery

    Battery "ground" (-)

    Output + (variable 12V DC) to lights

    Since OP has only 2 wires to work with they will most likely have to run a battery "ground" (-) to the switch location.

    I suspect that the OPs wiring is only Battery + and the switched + that returns to the light fixture and no battery (-) to be had...
  • There are a bunch of them on eBay. Just search for RV led dimmer.

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