Electrical open circuit / phantom load?

[Knetski]

Hi Everyone,
Looking for some advice troubleshooting an electrical issue.

Issue is that my interior lights are very dim and still work when I pull the lighting system fuse! In fact they still light up when I pull every fuse on my converter panel (except main battery power breaker).

Some background: Battery is recently replaced and fully charged. Of my interior lights that actually work, they are LED bulbs, the two fluorescent ones don't light at all (low voltage?). I checked the system for a phantom load and there isn't any measurable current draw on the system when nothing is on except for my propane detector (which disappears when I pull the fuse).

From what I can find online, sounds like I may have a phantom load or open circuit (can't find a decent definition of what I am experiencing except for on this site : https://itstillruns.com/electrical-s...v-7335027.html ) and I need to check continuity on the lighting circuit but I am not sure where to start or exactly how to do that. Would like to avoid ripping off all my interior panels etc as we were planning on leaving in a couple days for two weeks in our van. I also don't have a wiring diagram for our van - 1990 Roadtrek Versatile.

As a side note I recently replaced the converter as per many folks advice on this board in the spring, and everything was working fine after that for a weekend trip in June. Just last week attempted to replace an old fluorescent ceiling light with a lower profile LED one, and this started happening (to confuse the issue, my coach battery shorted at around the same time so I thought that was the issue and replaced the battery).

This is driving me nuts! Any advice would be appreciated!
Thanks
Mark

[Bruceper]

It's possible you have a ground fault loop. Somewhere along the line, something is grounding (poorly) and creating a circuit.

[BBQ]

.

YOu have to start from the fuse box...

check every fuse... to see which has a draw.

[JohnnyFry]

If the lights are lighting dimly with the fuse pulled fou have some source of leakage. One possibility would be a blown fuse indicator LED, if your panel is fitted with these. LED lamps take very little current to begin illuminating so one test would be to replace a single bulb with an incandescent lamp and see if any of the LED bulbs still glow when the fuse is pulled. If they do not it is a leakage issue which may not be worth fixing if all lights are operating normally when the fuse is in place. If they are still glowing the leakage is more serious and probably warrents troubleshooting using a volt/ammeter.

[Mike]

Originally Posted by Knetski

Hi Everyone,
Looking for some advice troubleshooting an electrical issue.

Issue is that my interior lights are very dim and still work when I pull the lighting system fuse! In fact they still light up when I pull every fuse on my converter panel (except main battery power breaker).

Some background: Battery is recently replaced and fully charged. Of my interior lights that actually work, they are LED bulbs, the two fluorescent ones don't light at all (low voltage?). I checked the system for a phantom load and there isn't any measurable current draw on the system when nothing is on except for my propane detector (which disappears when I pull the fuse).

From what I can find online, sounds like I may have a phantom load or open circuit (can't find a decent definition of what I am experiencing except for on this site : https://itstillruns.com/electrical-s...v-7335027.html ) and I need to check continuity on the lighting circuit but I am not sure where to start or exactly how to do that. Would like to avoid ripping off all my interior panels etc as we were planning on leaving in a couple days for two weeks in our van. I also don't have a wiring diagram for our van - 1990 Roadtrek Versatile.

As a side note I recently replaced the converter as per many folks advice on this board in the spring, and everything was working fine after that for a weekend trip in June. Just last week attempted to replace an old fluorescent ceiling light with a lower profile LED one, and this started happening (to confuse the issue, my coach battery shorted at around the same time so I thought that was the issue and replaced the battery).

This is driving me nuts! Any advice would be appreciated!
Thanks
Mark

This seems to be the point in your timeline where the issue began. Since it's an older Roadtrek it may be something to do with the way they wired the fixture for the fluorescent bulb that you changed out for an LED. Was the FL bulb you pulled out the type with a built in ballast? I'm thinking Roadtrek may have used a fixed ballast in the fixture, like you see used in home applications, like drop ceiling fixtures or other applications that use the long fluorescent tubes. If it's not something to do with what happens when you plug a lower draw LED into what might be a "ballasted" fixture, I would try asking Roadtrek Service (if they're still in business? service@roadtrek.com) - maybe they can pull the original electrical diagrams/schematics and take a guess at what's happening. Have your VIN number ready or include in your email if you send them one. Although fluorescent bulbs can usually be replaced with LEDs, the fluorescent fixtures/wiring may do things differently. It might have something to do with the much lower draw of the LED bulbs in a circuit not designed for them. I'm not an electrical engineer, and don't play one on TV. Just a wild guess, really. Good luck.

[JohnnyFry]

These 12 volt fluorescent fixtures use a high frequency inverter rather than a ballest to get the high voltage to fire the fluorescent tubes. When converting to LEDs this circuit is normally removed and the LEDs wired to 12 volt power directly.

[Knetski]

Thanks for all the suggestions!

Turns out I must have blown the fuse switching the ceiling light and like one of you mentioned there is some voltage carryover across the converter panel which was able dimly light the LED bulbs.

Feeling sheepish but happy it's resolved.
Mark