Interior lights question

[Jfstang]

Today I installed an LED light fixture over the sink, and when I turned it on it lit for a second and there was a "ZZZT" and it went out. Now it appears the circuit's dead.
Here is some back story. I have an 05C190P, and last year noticed the incandescent interior lights became warm over time. So I replaced the ceiling lights beside the 3rd seat, beside the bathroom, and over the centre of the bed (the big circular light) with LED's and they worked fine. These LED's were not particular about polarity, the wires were both the same color, so I connected them up and all was good.
Today I decided to replace the light over the sink (not the little one over the stove, that's still incandescent) with a new LED light. This LED light had a red/black stripe wire and a black wire. I connected them to the red van wire and the green van wire (ground). As soon as I turned it on, it shone for a second and went dead. Coincidentally, I found my LED over the center of the bed was now out as well.
But, the overhead LED lights beside the bathroom and 3rd seat, both of those still work fine.
So, I proceeded to RESET the GFCI outlet beside the rear side passenger door, and RESET the GFCI outlet by the microwave. The outlet by the microwave works fine (tested it with an old incandescent nightlight). I tested the red wire for the sink light with my voltmeter, there was nothing there.
Is there a fuse I need to replace somewhere? And can I still install an LED over the sink, or should I just put the old light back in if I get power again somehow?
Thanks in advance, all help is gratefully appreciated.

 

[GeorgeRad]

Your story is a little confusing, assuming LED lights were 12VDC why did you check GFCI 120 VAC outlets? Did you look for your new LED lamp manual, was polarity hookup necessary?

 

[Jfstang]

Good points.
Resetting the GFCI outlets was more of a reflex from my working with circuits in my garage (house electricity), you're right they wouldn't have much to do with the RV's 12 volt systems. I goofed there.
The wiring instructions were "Red and black wire connection, just connect the red wire to the power "+" pole and connecting the black wire to the power "-" pole. Use in kitchen, study, car, boat".
I hope I didn't bugger something up too badly.

 

[avanti]

For starters, ALL LEDs are polarity sensitive. If your first set didn't have different-colored wires, then it is almost certainly a 120VAC unit that has internal electronics to convert to low-voltage DC to make the LEDs work.

From the behavior you describe, I am guessing that the failed units were simple LEDs, most likely set up to operate on 12VDC. If so, is there any chance that you tried to run it from 120VAC? Sure sounds like it from the behavior. Or, perhaps you had the polarity reversed? Just guessing.

 

[Jfstang]

Makes sense about the LED's being internally modified to low voltage. I hooked the light today up, and it had differently colored wires (red and black), the earlier LED's I had installed had both wires the same color (white if I recall correctly). At any rate, I hooked them up red - to- the RV's red, black-to-the RV's green. And it then shorted out. The RV wires I connected it to were the same wires I disconnected from the RV's incandescent light over the sink.
Where should I look - a fuse somewhere, or a breaker? and if so, where would they be? I sincerely hope I don't need to disassemble woodwork, microwave, etc etc. to fix this. And I thought as I started, just a 3 minute job! lol

 

[GeorgeRad]

I think you have 12VDC light, correct? Some LED lights/bulbs with built in diode bridge can take any polarity, without it they must be connected plus to plus and minus to minus. LED with the same color wires likely have diode bridge built in, with black/red wires not. All main fuses should be on your main fuse panel.

Are there other DC devices not working?

 

[booster]

There are also a lot of poor quality LED lamps being sold these days. Competition and tough economies in the country of origin make for some sever cost cutting a quality reductions. I know people who have over 10% of the ones they received doing the same thing that the poster had happen.



It is lucky it didn't cause a fire as it failed, I think.

 

[Jfstang]

RESOLVED:
I traced out the circuits and electronic graphics as listed in the 2005 Roadtrek Manual, found that circuit 10 (if I recall right) powers the centre light, front light and sink light. The other ceiling lights are on a different circuit. Removed the couch/bed cushions, opened the fuse panel, and yes that 10 amp fuse was blown. Put in a new 10 amp fuse (offending LED light removed and old incandescent re-installed) and all works perfectly now.
In summary - as Booster and others pointed out - stay away from cheap polarity-specific LED interior lights. This forum is great, thanks all for your help, much appreciated!