Bedroom lights dim, then go out

[Newt5005]

Hi all-
2017 28.5 RSTS. I have had this issue for some time. Took it into the dealer and they said they couldn't replicate the issue so they couldn't (wouldn't) fix anything. I have explained this is not a consistent issue, to no avail.

Bedroom ceiling lights will occasionally dim. This has happened when the lights were already on and also when they were turned on. During the latter situation, they are the same dim when last turned off.
Sometimes they get gradually dimmer until they are no longer emitting light. Other times, they partially dim and then return to full brightness. When they return to normal brightness, it's not gradually, it's full brightness when turned on.
The condition can and has happened both when plugged into shore power and when running off battery. Current situation is lights started to dim when on battery and continued to dim after connected to shore power. As of last night, completely off (switch on).
I believe its's the controller or Driver running the LED's but there's 3, mounted on the lid of the front storage and do not know how to check them for function.
Again, none of the other lights in the coach are effected in this manor, just the ones on the ceiling. This includes the reading lights over the bed and the light (separate switch)in the bedroom wardrobe slide, as well as all of the lights in the main living area or exterior do this either.

[JimD]

Are those 3 separate lights? If so they should be independent of each other. This means each light would be fed 12 volts. I assume the lights aren't on some sort of dimmer switch that is going haywire.

If this is just a standard lighting circuit, you would probably be feeding the first light with the 12 volts from the switch plus a ground wire. The other 2 lights would be in parallel with the first light.

A bad ground could be resistive enough to dim the lights. A resistive switch could do it but most often just exercising the switch will clean its contacts. If these lights are on their own fuse I would pull the fuse and reinsert in case it is not making good contact.

Odds are you will need to get a voltmeter and measure at the light to see what is happening and then trace from there. It may be helpful to find the model of light being used.

[Newt5005]

JimD-
Thanks for the reply.
Not foreign to a volt meter, my first one was a Simpson 260, which dates me horribly. I have since updated.
Tonight, I checked the voltage at the fuse in the panel and read 1.4 volts to ground which was quite confusing. I pulled the fuse and read one side, zero, the other 27.6, again, quite confusing. I took a close look at the holder and noticed it was not actually (physically) grabbing the fuse on the hot leg of the fuse panel. The fuse leg itself was slightly oxidized. I cleaned the fuse leg, pinched the holder sides down so they were close enough to rub the legs of the fuse and plugged it back in.
Lights are full and bright. I can only assume the fuse was not in complete electrical contact with the holder.
It’s fixed “for now”, maybe for good. Only time will tell.
Thanks again.