02 Concorde loss of dash lights.
 

First off all electrical components and lights elsewhere on the vehicle are working fine. A couple of nights ago the dash illumination quit working except for the digital displays, cel and seatbelt. Turned the car off to run and errand, came out, started the car and dash lights were working fine. Turned car off for the night. In the morning upon starting no dash lights again and still none as of last nights driving. Soooo upon a little surfing it appears that these vehicles may have a concern with the 12v inverter located behind the instrument cluster guage for the incandescent illumination material. Hope that was said right? Viewed a you tube video about replacing that item. Just curious though, has anyone had this experience and what did you do to fix it. Replace inverter or replace the whole instrument cluster guage? Also, could this be the behavior of a bad headlight switch? Thanks for your time.

Could be the switch or the power supply. "Roll" the dimmer up and down a few times, see if that helps. Do the interior door/map lights come on with the switch roled all the way up?
If yes then the power supply is suspect.

The switch is working in all modes. Dimmer works also. Have to verify power out from the switch. If none them must be the 12v inverter.

It's intermittent. Had no dash lights yesterday in the a.m. Stopped briefly for an errand. Started car and had dash lights. Could be the switch? Interesting.

I haven't been able to dig into this issue recently. Dash illumination is still intermittent. What I have noticed is that when it is working and I operate the switch I can hear what sounds like a relay clicking when I go from off to auto. When the dash illumination is not working you can not here the clicking sound when going from off to auto. Sounds like it is coming from somewhere behind the headlamp switch but not too close to the switch. Apparently something is not allowing power to the switch on occasion.

Well at this time I still haven't dug more into this issue. Dash lights are still intermittent and appear to be more readily to work during colder temps. Anyway I went ahead and purchased a small $3 battery operated led light that I Velcroed to the steering column. Just turn it on to illuminate the speedo, tac, and temp gauge. Surprisingly it lights up enough that it is pleasant to the eye for night driving. Odometer still is illuminated along with dash clock, headlight bright light, and cel as I have a small evap leak code at present.