I have a 98 that has been pretty much been completely rebuilt, including the interior. I seem to be having issues with some of the interior illumination, which is one of the few things left to iron out. I cannot find any blown fuses (dash/bay), and have replaced all of the dash fuses recently, after this problem occurred. To troubleshoot, I replaced the dimmer dial with a boneyard part... to no avail.

When I turn the headlights on, these DO NOT illuminate
1) Gauge cluster back lights
2) Front window switches
3) HVAC control icon backlight (the green 'selected' lights work)

When I turn the headlights on, these DO illuminate
1) Headlights (switches relay for HIDs in a set of 03 headlights)
2) Odometer backlight
3) REAR window switches
4) Sidemarkers
5) Tails

These, I have no idea becasue they have been removed from the car
1) Radio (I run no head unit, all my music comes from my Android devices directly to an EQ then a JL amp)
-- though it seems as though the switched and constant 12V for the radio do not work (by test light)
2) Clock (long gone)

These work as normal, with/without ignition
1) Door panel lights (door open)
2) Dome Light (switched + door)
3) Map light (switch)
4) Check engine / door / brake status lights
5) Brake lights
Any suggestions? It's a pain not to be able to see my speed at night.

 

could it be something as simple as old incandescent bulbs being burned out?

Clock is a simple re-solder fix. First "mod" I did when I bought my 99SE.


you have normal dimmer operation with the rear window switch lights, yes? Did you or anyone else replace the gauge cluster lights with LEDs? If so, remove cluster, remove from cluster and re-insert, 180*.

 

I do have LEDs in the gauges, and they worked for at least a year before all of the illumination I mentioned went out. Also, the window switches in front and rear have blue LEDs installed with appropriate current control. Both rears still illuminate. Both fronts do not.

Would a simple bulb out make the front window switches, the gauge cluster, AND the A/C backlighting nonfunctional simultaneously? A/C has stock lighting, and does not illuminate.

Also, I have a blue LED in the ignition ring. Also does illuminate when door is open.

I don't care about the clock. I sold it 8 years ago.

The rear window switches do not dim when I turn the dimmer dial. Do they normally?

 

I believe they should dim as well...yes. I know my fronts do, I'd think the rears as well though I have tbh, I haven't checked.

one bulb out make them go poof? Not likely. Unless the LEDs you bought were super cheap, and one is now shorted or something...but it's *possible* I suppose. No need for separate current limiting resitors in the window switches, BTW...your 98 is the same as my 99 and has LEDs already there, no need for more resistance (less brightness)

Check all the wires to the A/C unit, including the ground that's there..maybe you're not grounded well enough.

and you're sure the 7.5A "int illum" fuse left of steering wheel is good and in proper position?

 

There is no dimming going on for the rears. I guess that is another symptom?

The Int Illum fuse has a 10A in it and is intact.

The AC control works fine, I'm uncertain what to do to check ground that is specific to the illumination and how that would affect the window switches and gauge illumination.

You're right on the window switches. Just swapped out LEDs. Same for the ignition ring.

I'll check all the LED bulbs in the cluster 1 by 1 to make sure.

Has anyone had an issue similar to this? Did not find anything new in search.

 

the backlighting for the cluster AND the window switches AND the climate control all runs through the dimmer...if that circuit is not proper, the above could very well be off.