Illumination Issues Heater Control Panel

[carcrazyguy]

Just as the title says, there is no ilumination behind the heater control. Also, the car is an automatic and the shifter backlight does not light up either. However the instrument in the center (speedometer, etc) light up and work just fine.I measured a measly 3V at one of the bulb holders when the dash lights are on. The bulb itself was OK when more voltage was put to it.Does anyone have any idea what is going on here? If this has anything to do with it, there is currently no stereo in the car.

[s14_240sx]

Is this in an s13 or s14? there are alot of things that can go wrong, but the fact that your speedo lights work is a good sign. Do any other lights work anywhere else in the car?

What usually happens is that the bulbs burn out in the hvac controls or the connection between the hvac and the hvac control bulbs get worn out.

What you'll have to do is change the bulbs.

[carcrazyguy]

This is an S13.I initally wondered about the bulb inside the HVAC control and wanted to pull the HVAC control panel out of the car, but never actually figured out how to remove it completely, and didn't want to break anything to remove it. I guess I will search around for that. Regardless, since the illumination for the shifter and ashtray are not working (yet with good bulbs) then the bulb in the HVAC is likely OK too - and the problem elsewhere and related I would think.Another thing I noticed is that the dimmer switch on the left of the steering wheel has no effect at all - in other words, no matter what you do with it, the dash stays lit the same. Any ideas?

[topairhead]

hey my ac lights dosent work 2 . also my cig. light dosent work well the cig box is broken .i tried fixing the cig light but its a tiny bulb and i dont know how to take it off.anyone?

[NCturbo75]

This is an S13.I initally wondered about the bulb inside the HVAC control and wanted to pull the HVAC control panel out of the car, but never actually figured out how to remove it completely, and didn't want to break anything to remove it. I guess I will search around for that. Regardless, since the illumination for the shifter and ashtray are not working (yet with good bulbs) then the bulb in the HVAC is likely OK too - and the problem elsewhere and related I would think.Another thing I noticed is that the dimmer switch on the left of the steering wheel has no effect at all - in other words, no matter what you do with it, the dash stays lit the same. Any ideas?

To pull off the climate control unit, it is easier to remove the stereo and pocket mount unit first. Once this is taken out, you can remove the four screws holding the climate control unit and lower it down where the stereo was. Then pry open the slot on the left (ontop of A/C unit) and you will be able to see the two bulb mounting "tabs". Just turn it counterclockwise and use something to pull them out. As for the dimmer, you might want to check to see if the dimmer switch is actually plugged in. If your car had a previous owner, he/she may have cut or totally removed the plug from the back of the switch.

[carcrazyguy]

To pull off the climate control unit, it is easier to remove the stereo and pocket mount unit first. Once this is taken out, you can remove the four screws holding the climate control unit and lower it down where the stereo was. Then pry open the slot on the left (ontop of A/C unit) and you will be able to see the two bulb mounting "tabs". Just turn it counterclockwise and use something to pull them out. As for the dimmer, you might want to check to see if the dimmer switch is actually plugged in. If your car had a previous owner, he/she may have cut or totally removed the plug from the back of the switch.

Thanks, I will look into that tomorrow if the weather is OK. That makes sense that maybe the switch is bypassed or something.BTW, do you know if there is a control unit for the illumination system?

[NCturbo75]

I'm not sure if there is any. I believe that all the dimmer controls is in the the dimmer switch itself. Perhaps, you might have a bad switch. It's worth a look.

[carcrazyguy]

I'm not sure if there is any. I believe that all the dimmer controls is in the the dimmer switch itself. Perhaps, you might have a bad switch. It's worth a look.

I will check that out for sure. If that is all it turns out to be, that would be too easy!I guess I also need to browse over the schematics for the ill. system in the FSM too.

[ISUJinX]

FYI, Illumination for HVAC is o na separate circuit than the the dash lights. I'm still working on getting my HVAC stuff to light up after my RB swap, but my Dash works just fine. As for my cig lighter.... thats another story all together. My fuse box is somewhat melted around that area :-p

[carcrazyguy]

FYI, Illumination for HVAC is o na separate circuit than the the dash lights. I'm still working on getting my HVAC stuff to light up after my RB swap, but my Dash works just fine. As for my cig lighter.... thats another story all together. My fuse box is somewhat melted around that area :-p

How can the dimmer work on both if they are not on the same circuit?

Anyway, I am not worried about the cig lighter bulb, as I always remove the whole bulb and harness when I get a 240 since don't smoke and the illuminated ashtry is a little distracting anyway. However I would like to get my backlighting for the AT shifter working which is very likely related to the cig lighter bulb, I would guess. I will dig into this as soon as winter goes away again - it finally got below 60 here but should be back to it on Thursday if I remember the forcast right.

[OldmanPurdy]

I had problems with my HVAC lights too when i got my car (lots of others too it seems). Occasionaly the lights would come on when i hit a bump though, the solution for me was cracked solder joints on the HVAC circuit board. Just a matter of re-soldering any shifty looking ones.

[s14_240sx]

You said something about your dimmer switch not working? this sounds like a common problem, basically the dimmer switcch shorts out and screws things up. When it shorts out all the dash lights are on the highest illumination setting. check that out first. I had none of my hvac controls light up in my s14, and the problem ended up being bad bulbs and/or bad contact points. It took maybe 30min the first time to change them all (cuz i had to find out how to open it without breakin it). I even made a DIY write up, but i haven't got around to posting it. If theres interest then i'll post it up.