Dimmer wiring

[Wazz_zup]

The lights in the bathroom are just way too bright for me. Unless I want to see where I missed shaving. I bought this 12V dimmer switch and need to know how to wire it up.



Here's my wiring for the bathroom. Bedroom looks to be the same.
Are the whites with a green stripe the ground? Connect those to the black wire on the new switch?
Should I split the reds on the trailer wiring and multimeter to see which one goes to the light and which goes back to power from the rv?
Disconnect the switch before hooking up the multimeter to the rv wires, right?

[FT4NOW]

On the switch, the black should goto ground which should be that white wire bundle you have, the red goes to +12v and the white goes to the lights. With the current switch you have turned off, take a voltmeter and you can see which one of the wires is +12v and which goes to your lights.

Sent from my SM-G950U using Tapatalk

[Wazz_zup]

Thank you FT. So of the two red wires going to the switch, separate them? Then put the meter on one or the other and the black lead of the meter to the white wire bundle to see which one gives zero or 12V? The zero volt I'd say goes to the lights. 12V goes back to the panel. I'm a rookie at this electrical stuff. I don't want to blow anything up!

[FT4NOW]

Before you disconnect any wires, turn the switch off. Then put the ground from the meter on a known ground (those white wires) and then put the positive wire from meter on the green, then switch the positive wire from the meter to the red. Which ever of those two show +12v will be your +12v source. The other wire is what goes to the lights. You will not need to separate any of the wires with the exception of creating a new splice. My guess is the green wire is the +12v since it's a single wire, but you never know, that's why you do the meter test.

Sent from my SM-G950U using Tapatalk

[Jerryr]

Unless you put a meter on it you’re just guessing.

So here’s my guess.

The 2 red wires are +12 v source
Grin/Wht is the load going to your LED light.
When you turn on the switch you connect +12v From Red wires to the Grn/Wht wire going to the LEDS

The white bundle is ground (neg).


So with the switch off:
Put your meter on 20v DC Scale
Stick your meter black lead into the white wires on the top-hat butt connector
Put your red meter lead on the red spade connector.
If I’m right you should read 12v

Move your red meter lead to the Grn/Wht wire
If I’m right you should read 0v

Turn on the switch
If I’m right you should have 12v on both spades on the switch.

But FTs guess may be right about the Grn/Wht being the +12v source and I may be wrong. Until you put a meter on it you won’t know.


Done.

[Wazz_zup]

Ok, thank you both very much. I didn't blow anything up. With the black meter lead stuck in the white wire bundle and the switch off, the green and white showed 0 on the meter. Then with the red meter lead, I went to the two red wire side of the switch (still off) and it showed 12V. Turned the switch on and both sides of the switch were 12V.
When the dimmer comes in tomorrow, I might be back for more questions.
But for now, the black of the dimmer goes to the top-hat white bundle....
The white goes to the green/white striped...
And the red gets spliced with the two red wires coming in. Correct me if I'm wrong.

[Jerryr]

Ok, thank you both very much. I didn't blow anything up. With the black meter lead stuck in the white wire bundle and the switch off, the green and white showed 0 on the meter. Then with the red meter lead, I went to the two red wire side of the switch (still off) and it showed 12V. Turned the switch on and both sides of the switch were 12V.
When the dimmer comes in tomorrow, I might be back for more questions.
But for now, the black of the dimmer goes to the top-hat white bundle....
The white goes to the green/white striped...
And the red gets spliced with the two red wires coming in. Correct me if I'm wrong.

Looks like you now have properly described the wiring connections.

[Jaymee317]

Ok, thank you both very much. I didn't blow anything up. With the black meter lead stuck in the white wire bundle and the switch off, the green and white showed 0 on the meter. Then with the red meter lead, I went to the two red wire side of the switch (still off) and it showed 12V. Turned the switch on and both sides of the switch were 12V.
When the dimmer comes in tomorrow, I might be back for more questions.
But for now, the black of the dimmer goes to the top-hat white bundle....
The white goes to the green/white striped...
And the red gets spliced with the two red wires coming in. Correct me if I'm wrong.

I also believe you have described the wiring correctly. You could also pull down the light from the ceiling and confirm that the white/green wire goes to the light. It doesn’t hurt to check. UNLESS that mousetrap bracket on that light gets your finger. Don’t ask me me how I know...

[Wazz_zup]

I also believe you have described the wiring correctly. You could also pull down the light from the ceiling and confirm that the white/green wire goes to the light. It doesn’t hurt to check. UNLESS that mousetrap bracket on that light gets your finger. Don’t ask me me how I know...

Good idea, and after seeing in there, that's a good way to describe them....mouse trap!

[Wazz_zup]

All in and works good. No flicker on the lowest brightness because it was the PWM style. Thanks again for all the help, I couldn't have done it without you guys!