Illumination Issue - Same Circuit?

[farmteam]

The following lights do not illuminate when I turn on the headlights:
Radio button lights (only the LED display panel illuminates and it dims when I turn on the headlights)
A/C Switch (only the green light illuminates when it is on and it dims when I turn on the headlights)
Defroster Switch - the normal 'off' does not illuminate with the headlights and the 'on' never illuminates

The passenger visor mirror light does not turn on - the bulb is intact and should work

Any chance these illumination issues are related to a single circuit / fuse with the headlights? The radio buttons, A/C switch and Defroster should all illuminate when I turn on the headlights but they do not.

Prior owner installed a Kenwood 10-CD changer mounted behind the driver seat. It has it's own control unit wired behind into the radio harness. It's an odd unit - plays CD's but they broadcast through the radio as channel 88.3FM. The CD's barely register on the left side of the speaker system even though the radio plays perfectly - might just remove the Kenwood system at this point.

[farmteam]

I tested the A/C 'off' and Defrost "off" and "on" lightbulbs this morning - all (3) work perfectly. The Hazards switch light also does not illuminate even though the hazards and blinker indicators are functioning when the Hazards are on. All (4) bulbs are new LED installations. These switch lights were not working before changing over to the LED's and I assumed they were old dead bulbs.

[originalkwyjibo]

In regards to this and your other thread regarding warning lights: In the past I have attempted to convert two vehicles to full led lighting in the instrument panel, ie illumination and warning lights. On my 1992 Saturn I had a similar issue with the charging light. Apparently the charging system factors in the resistence of the incandescent bulb for the indicator circuit. This car is a manual transmission and has an upshift indicator light for fuel ecenomy. The led in that indicator actually caused an engine code. My turn signal indicators were also on dimly all the time. I tried reversing the sockets for polarity without the desired effect. On my 88 van I did the illumination lights and tried a couple warning lights with similar issues as the Saturn so I just went with leds for the illumination. So, for the vehicles I tried this on, the verdict was not all lamp circuits play nice with leds. I would imagine you could add a resistor to those circuits to get them to function properly but I chose to put incandescents back in.
Apply my experiences as you see fit.

[man_btc]

I tried replaced my dash bulbs with LEDs years ago, if for no other reason than I tend to be a can't-leave-well -enough-alone type (yes I'm an EE). The directional indicators were wicked bright unless the dimmer was turned way down. A month into it the PRND2L lights started to flicker. I had put them in with resistors to limit the current flow, but obviously not the optimal ones, nor did I do any kind of QC other than ordering them from ebay and hoping for the best. At 1 month+ I went back to bulbs because repeatedly pulling the instrument panel and monkeying with things didn't feel like it was worth the effort, and went back to bulbs which lasted a long time anyway. Unless you're going for a different look for the illumination, I'm not convinced it's worth it.

[farmteam]

After changing all of my instrument cluster lights to LEDs, the Battery indicator and Low Fuel indicator remained on all the time even though there were no issues. The SRS airbag light was on due to my Code 54 issue but it would remain slightly on even when the ignition was "Off" and the key removed. I changed all of the cluster indicator bulbs back to incandescents (except turn signals and general illumination) and the Battery, Low Fuel, and SRS lights are back to normal. Still need to resolve my Code 54 error in the SRS system.

I now believe power for the switches (A/C, Defrost, Hazard) and radio illumination (turn on with headlights) is powering the Kenwood 10-disk CD changer unit. I pulled every fuse and all are fine - there is no blown fuse preventing the lights from illumintion with headlights. The passenger visor mirror light also does not work eventhough the bulb is fine.

[farmteam]

Apparently there is a loose connection in the mess of radio / Kenwood CD changer wires. For no reason, ALL of the radio button lights, the A/C switch light, and the passenger visor mirror light worked last night when I turned on the headlights. They were not working yesterday after I gave up and reassembled the dash. The Defrost and Hazard switches still not illuminating - but I have 'some degree' of improvement - might be short-lived. Kind of afraid to take it all back apart to get the Defrost & Hazard switches to illuminate as I might lose all of them again.