Electrical – Bedroom 12 volt issue

My ceiling light fixture in the bedroom, even when it’s working doesn’t give much light…but it’s attractive. It is controlled by a fader control on the wall, operating on 12 volt. Typical bedroom ceiling lights in an RV are not very bright to begin with. So you live with it. I like the fixture’s attractiveness and it’s not had an issue until recently when the fader just stopped working. The lights are dark. They are now Dark Emitting lights. I measured the resistance of each small bulb in the fixture and all of them register as good.

Usually at night I need light emitting fixtures so I guess I have to fix this problem. Here’s a shot of the fixture in the ceiling over the middle of the bed.

Here’s the fader control that’s mounted on the bedroom wall.

And here is where the two wires that run to the fader and then the light fixture end up. In one of those multi-wire connectors. With the mostly yellow and some white wires. According to my Winnebago wiring diagram, there’s only suppose to be one multi-wire connector in this cabinet. Gah!

What I did so far was strongly wiggle the wires in both those connectors, applying force in the ‘connecting’ direction so if there was a loose wire or a connector making poor connection, manipulating those connectors should have shown it up and given me a bit of light from the fixture. Unfortunately, it did not. So I now have to puzzle it some more.

And the back side of the fader. I measured the red/white wires and I’m seeing under 4 volts DC there when the knob is turned to ‘low’ and it goes lower as I turn the control knob. When set to ‘Off’ I measure 12 volt. Since I’m seeing ‘some’ voltage, it’s not a blown fuse. Symptoms possibly indicate something internal to the fader controller is bad. So, time to pull it apart and check components.

First thing I did after removing the fader was take it apart and just look at it. I was looking for a melted or blown part. It’s a nice bit of modern electronic work and should last for decades. Hmm. Okay, I’m not just going to assume and toss it. It looks too good.

Since it looked so good I decided it needed to be tested rather than just replaced and what I did was grab a spare 12 volt bulb I have and connected the fader up to the bulb and than to the 12 volt power supply I’m currently building. And it worked fine and controlled the bulbs brightness just as designed.

A word about the power supply there on the left: It’s capable of being adjusted between 12 volt and 55 volt DC. At 10 amp max. Using the RV’s handy cigar lighter sockets as a 12 volt source which are in several convenient places all around the RV. Those sockets and the power supply will be handy when I need to test something independent of the RV wiring. This handy little DC Booster is available at eBay for a few bucks. I haven’t finished building a fancy case for it yet so that’s why it looks raw.

So now that I know the fader is still working, that I have good bulbs in the fixture, that wiggling and tugging the wire bundles in the TV cabinet didn’t restore operation, it’s time to remove the fixture and see what’s up inside there.

So there are a couple crimped connections (higher up and cropped from the top of the above picture) and a couple wire nut connections. I left it dangle and shorted out the two wires over where the fader goes. Sure enough the light came on. So that told me there’s a loose connection in there somewhere and the weight on the connections when it dangled restored it. I took my large pliers and squeezed the two crimped connectors, then loosened and re-tightened the two red wire nuts. Gave them all a good tug test and the light stayed lit.

So that’s it’s, a loose connection under the light fixture. Didn’t really find it but don’t think there’s a need either. I would bet a bunch of bucks that the average shop would have ordered and installed a new Fade controller for a couple hundred bucks instead of going as far as I did to find the issue.

So that’s the story. Not as satisfying as actually finding and fixing whatever was wrong, but I’ll remember and redo those connections if it happens again. Thanks for reading!

One Response to Electrical – Bedroom 12 volt issue

  1. Tom Blevins says:

    We never used the dimmer, just turned the light up for almost adequate light. So I replaced all the bulbs with LEDs and replaced the dimmer with a regular on/off switch. We dry camp from time to time, so more light with less power use is a winner

    I can understand throwing away 5 perfectly good bulbs likely to last another 18 years but not that beautifully designed dimmer circuit. It’s just too well designed to be treated so cruelly.

    I don’t do much boondocking since it’s so easy to find places to park for under $13/night with all the services and I’ve averaged just $380/month over the last 17 years of full timing. I have looked into solar systems several times but so far every time while investigating it I get to a certain point of information overload and put it aside. Ha!

    I don’t see where it would be saving much energy just removing 5 small bulbs and replacing them with $7 each LEDs considering how little the bedroom ceiling fixture is used. I can understand replacing the reading lamp bulbs though.

    Anyway, to each his/her own I guess.

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