Basic Electrical Question

[rjd_in_virginia]

My Beneteau 46 came with a dimmer switch for the 6 main saloon overhead lights. I upgraded the lights to G4 Bi-Pin LEDs. In this configuration the lights reduce to a faint glow but do not turn off completely. The dimmer switch has 3 wires: Black, Red, Orange. The Lights have Green and Red wires. The dimmer switch Black is connected to the Black going back to the 12v panel. The dimmer switch Red is connected to the Red going back to the 12v panel and the Red to the Lights. The dimmer switch Orange is connected to the green going to the lights. Here are the voltage drops:
Black - Red 14.3v
Switch OFF
Red - Orange 8.4v
Black - Orange 5.7v
Switch ON
Red - Orange 13.2v
Black - Orange 1.0v
I would expect with the the switch off, Red - Orange should be 0v. Any thoughts what's going on with this circuit, bad switch?

thanks
rjd'

[Lake-Effect]

Can you tell us the make and model of the dimmer switch?


I have not laid hands on a commercial 12v DC dimmer switch, but I would have expected that the dimmer would have been switching the +12v side (red), and the negative (black) would be the common going straight to the lighting.

If I'm right, the correct hookup would be to connect the lighting's green wire to the junction of the two blacks, and then connect the lighting's red wire to the orange coming from the dimmer.

But I don't recommend trying anything different til you know the dimmer's make/model and can look up their instructions.


(also, a dimmer made for regular incandescent bulbs may not be happy dimming LEDs. Again, the dimmer's instructions should cover this)

[Zil]

My overhead with dimmer does the same thing after I changed to LED. They will go off but then return to a very low glow.

[GordMay]

Greetings and welcome aboard the CF, RJD.

[dfelsent]

It’s actually an interesting issue, and not that basic.
LEDs are efficient enough that even the leakage current in some dimmers lets them glow. That current was likely there with the incandescents but not enough to make visible light.
As a thought, adding one small incandescent somewhere might stop the led glow by diverting the current. I’ve done similar things in other cases.
Or add a separate on off switch.

[rjd_in_virginia]

Lake-Effect asked the make and model of the switch so i went through my pictures. It's a FRILIGHT and right under the name it says Halogen Dimmer. Lesson learned: read the instructions! Since I like the LED lights, it looks like i'll have to replace the switch. Thanks for the help!

rjd'