Instrument Cluster & HVAC night lights are off, but all other lights are OK?

[michaelb721]

Hi,
I just had something new come up, and I could use some advice what to check next. When I drove home Christmas evening, my night lights on the instrument cluster and HVAC controls did not light up at all, but the red radio backlight was fine and the dimmer switch worked on the radio light too. All other exterior lights, interior lights, DIC, courtesy lights and dome lights seem to be working OK as well. The green instrument turn signal lamps work when in use, and the warning lights flash on/off during the start sequence. HVAC controls themselves work fine. I just don't have any night lights in those two areas. I checked what I thought were the most obvious fuses inside the glove compartment, but didn't see any blown. (I would have pulled them all one by one, but it's too cold outside to do that right now!!!) Does anyone have any idea what to do next? Any suggestions will be appreciated.

[Scottydoggs]

try turning the dimmer switch on the headlight switch?

[michaelb721]

That was one of my first thoughts too, but the dimmer switch seems to work OK. Turned all the way to the left, the radio backlight goes off; turned all the way to the right the backlight brightens, and at the last setting, the dome lights come on. However, the instrument cluster and HVAC lights stay dark. Thanks for a good guess though.

Edit to the original post: Seems I forgot to mention the steering wheel control lights don't light up either. The wheel mounted radio controls still work fine; it's their night lighting that doesn't work. More joy! :P

Had another thought this morning: I checked to see if the fuses were blown, but I didn't think to check if they were in the right slots. Have to double check that when I get the chance. Right now duty calls and I'm off to work...

[michaelb721]

Finally got the chance to complete my fuse inspections after the heavy rain quit. All fuses in the glove compartment, and under the hood are unbroken, the correct amp rating, and in the correct spots. At least that's ruled out.
So, if my Haynes repair manual electrical diagram is right, then all my trouble can be traced back to... the dimmer switch. Huh. (Haynes latest included interior lights diagram was for a 1995. I guess it's the same for 1998s.) There are apparently two separate circuit paths from the dimmer switch. One controls the night lights for steering wheel controls, instrument cluster, heater & a/c controls, headlight switch, fog light switch, ashtray light, and the left & right door lock and window switches. I double checked, and they are indeed all out. (Didn't think it was all that many, but it is!) A second isolated circuit path goes to the radio; and that's probably why it still lights up and responds to the dimmer settings. I'll change out the dimmer switch and see if that cures it. Scottydogs may have been right after all, just in a slightly different way.

[Scottydoggs]

i could see that acting up like that. its worth a shot.

[nos4blood70]

I hope it's just a dimmer switch for simplicity's sake. My car decided to short somewhere in the dash harness. So now I don't have that red glow I know and love.

[michaelb721]

I hope too. I don't fancy the idea of tracking down a short the hard way.

[michaelb721]

The new headlight switch did the job! Just got back from my night time test drive, and all the lights inside and out are properly lit and responding to the dimmer setting now. Fixed!
Ah, the comforting red glow of night lights that all work again...