Dome lights work, switches don’t.

[firefighter_2000]

The dome lights on my truck work fine when I open any of the doors, or when I turn the switch under the headlight knob to the far right. They do not however work when I reach up and hit the actual dome light to turn it on with the doors closed/dome light switch off.
As an added bonus, when I have a door open, I can reach up and push the dome light and the light will go on and off.
Anyone have any idea where the disconnect or whatever might be? The only thing that I can think of that has changed recently is I had my windshield replaced a couple of weeks ago, but not sure if or how that could have affected it.
Thanks
Craig

 

[Whitewolf]

Wow. I've had 'em go out on my '14, but never that.

 

[Timd32]

There is a harness that runs up the pillar.
It would not be out of the question that possibly could be damaged during windshield removal, not sure, the last thing touched is always a great place to start.

The Yellow / Light Blue is the circuit from what I can tell.

The overall +12v circuit is BCM controlled. Ground is at the lamps all the time, so they work grounds are good.

The Courtesy circuit (Yellow/Violet) lights the lights when the doors are open or the little wheel switch is turned. That appears to be separate from the Reading Circuit (Yellow/LT Blue)

Looking at the diagram the reading lights are part of the door box lights and glove box, vanity lights, and rear dome.

Do any of those work? Only some, say try the door boxes, glove box, left and right vanity lights, rear dome. See what works what does not.

These are part of the BCM powered RAIL LMP FDS circuit (Yellow / LT Blue). The ground looks to be there all the time, it does not show the individual switch operation for any of these. So if the local switch controls the ground makes sense the light would turn off when the door is open and button pressed, it's opening the ground side, but power in that case is from the Yellow/Violet wire.

Doors closed and wheel switch off, power is from the Yellow / LT Blue.

The dome and reading have a 3 pin wire connector, where the glovebox is only fed from the Reading Circuit (Yellow/LT Blue)

But if the Glove box works or vanity lights (thinking those are the sun visor mirror lights) you can atleast rule out a BCM issue where it's just not sending any power out.

There is an overall connector I370, then there is a splice in the headliner.

You could check that connector, and the glove box deal, side boxes, mirror lights, that will go a long way.

I think your dealing with the Yellow/ LT Blue circuit Pin 10.

Good luck chasing this down.

FYI many references say need a scan tool to diagnose the BCM side of this. Could also check for any codes.

 

[firefighter_2000]

Thanks for all of this info Tim! I’ll start chasing this down tomorrow. Doesn’t look like it’s going to be fun!

 

[Timd32]

Just in case it's something pretty dumb here is the bulb list.

The dual circuit fed reading lights don't look like dual filament, they appear to only have one connection, but just in case it's just a bad bulb.

Lots of warnings to use the correct bulbs in these areas.

 

[firefighter_2000]

Thanks to Tim, I was able to trace everything back to the BCM. ONE item is not functioning and I’ll have to replace the entire BCM. Same thing a few years back... The drivers door lock stopped functioning and it required a new BCM. Oh, and it has to be programmed by the dealer. What a PITA.