overhead lcd in tahoe dome light woes

I did a search first.. :)   And it looks like Joe (https://www.the12volt.com/installbay/forum_posts.asp?tid=73100) had a similar issue to me. There is definitely something funky with the Tahoe wiring..

I too am having to deal with an overhead LCD/DVD setup that has its own dome light (and issues).

I think because the Tahoe overhead Dome Supervision light gets variable voltage (i.e. a dimmer), it screws up the new overhead dome lights which expect an "on/off" positive voltage level from the car. My DVD player can do negative voltage too, but I don't think that's correct. I have an '03 Chevy Tahoe.

In any event, my wiring is as follows:

orange from oem dome light ---> + on new dome light
black from oem dome light ----> - on new dome light
gray from oem dome -----------> + trigger on new dome light

It seemed like it was working fine when I was installing it. But now that it is in, it isn't working right. I don't know if I loosened a wire when installing it or not, but I am pretty sure I didn't as I used really good crimps.

So the weird thing is, my new dome light won't even come on at all.... even when I force the 3-way switch to the ON position... THAT IS, UNTIL I press my driver's map light button ONCE while the (other) dome lights are on. Then the new overhead dome light comes on suddenly as if by magic. I also hear at the same exact time, a click from a relay or something down by the main fuse panel next to the steering column.

So the map light somehow causes the grounding or voltage to be right for the new overhead light. I don't know why, though, and that's what I need to figure out. I was thinking maybe when the courtesy lights go out, since they are on a dimmer, they never really go out properly, and leave the new dome light thinking there is no voltage there. And then when they come on again (when I open a door), it ignores the voltage increase and does not permit the new dome light to come on. Then when I hit the maplight button it sends a jolt to the new dome light virtual circuit and get it to come on.. *shrug*

HELP!! :(

Thanks!!

Hmmm, i've done a hundred Tahoes, installed Avox, Advent, Artis, Myron/Davis, Feirenheit, Rosen DVD's in them and can't recall ever having an issue with the dome lights working. I know this doesn't help much. Maybe if you tried running the positive trigger thru a relay and flipping it ground, then using the negative input for the domelights on the DVD...

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Mike M2
Tech Manager
CS Dealer Services

What brand of DVD are you installing? Rosen had a bulletin about not using the OEM wiring for the domelight in those vehicles. From what I remember you ran the power and/or ground wire direct and only tapped into the trigger at the OEM domelight.

Mike