12v House Ground Points

[Eggbert]

I'm chasing down some ground issues on the 12v house circuit.


Specifically the 12v lighting in the bath and bed area.


Can anyone tell me where I can find the ground points to clean and tighten on my 2003 40FDTS?

[Old Scout]

Not sure you will find the answer here--but, 12v house fuses are under the sink cabinet in the bathroom. There is a large 12v grounding bus by the inverter/charger in the basement--not sure how the 12v house grounds are made.

[andy29847]

12vDC circuits return to the negative side of the battery.



I'd like to know what kind of gremlins you are chasing.

[Eggbert]

Long ago I converted the florescent tube lighting to non-ballast LED tubes. No problems for years, high quality bulbs, everything worked great until… I put some bright LED bulbs in the bathroom vanity.

Now when I turn on the vanity all the LED ceiling tubes in the bed and bath (12v purple circuit) flicker or glow even though the tube fixtures are "off" at the wall switch.

Somehow a small current is being triggered in ceiling tube lights.

The bathroom vanity uses the 1156 automotive style bulbs. So I decided to try the bulbs in other fixtures on the same purple circuit (bedroom vanity & toilet ceiling) with the same result, flickering tube lights.

I checked all my grounds and decided to replace all the wall switches to spruce things up and maybe fix the issue (it didn't).

What has me tearing my hair out is the flickering and glowing still happens even if I completely disconnect the tube lights at the wall switch.

I can stop the flickering for an individual ceiling fixture if I turn off the switch built into the fixture base.

I measured 30 to 50 mA (fluctuating) on the ground wire at the tube fixtures with the vanity LEDs on.

Where is this current coming from?! What's the actual issue I've uncovered?

There HAS to be more to it than just a misbehaving bulb. Any ideas?

[d23haynes57]

Does the switch have a dimmer and/or an indicator light? Is there more than one switch controlling the lights such as door switch or a remote. Having weirdness's with LEDs are not that unusual and sometimes load resisters need to be added for certain controls to work.

[Eggbert]

Each fixture is controlled by a single non-lighted wall switch. All the wiring connections at the switches are clean and tight.

No dimmers, lighted switches, or door switches on this 12v circuit. I will devote more attention here.

Funny you mention resistors, in the multi-bulb fixtures like the vanities if I add one incandescent bulb alongside the LED bulbs in the fixture it *almost* eleminates the issue (like 99.9%).

I am only familiar with using resistors as a bandaid in the brake circuit to create load for a flasher module.

[swinters]

I had some strange things going on with the 12V side of the coach on mine when I bought it last year and the only thing common to the circuits on mine was the ground, so I started with cleaning the grounds to the frame and then after digging around found a ground buss on the rear wall of the basement compartment that's right in front of the rear axle (also the compartment my Hydro-Hot is in). It's about 8 inches long with a bunch of ground wires in it, I'd guess maybe 50 wires, and several of the screws that held the wires in it needed tightening. I made sure they were all tight and then loosened the mount screws for the buss bar and then retightened them and my problems disappeared. I had also cleaned and tightened all the ground wires at the batteries and frame mount points, so can't say for sure what did the trick but I'm sure that in my case it was a ground issue. Like they say, electricity takes the path of least resistance and if it can't make it through the ground circuit it'll find somewhere else to go.