This DIY is for people who’s climate control lights have burnt out. Before pulling the hvac, use a multimeter and test the middle hvac harness to see if it is giving power to the lights, (the red with blue strip is the positive and the red with yellow strip is the negative) if it is getting power but your hvac isn’t lighting up, then your bulbs are blown. This is the harness i'm talking about
Another way of checking to see if it is infact only the bulbs that are burnt out is to check around for any other lights that work. For example, on my s14 the light that lights up the “driver window” button had a light in it that could be controlled by the dimmer switch. If all your lights are not lighting up, the dimmer switch has no effect or your not getting power to your hvac light wires, than your problem lies else where. Some say the dimmer switch shorts out or the TCU is burned out.
Heres a link for the TCU that seems to solve a lot of peoples problems.
zerothread/158162
Ok lets get started. This is the hvac unit we all know and love. If you don’t know how to get your hvac out, I don’t suggest you even try to fix the lights yourself. First you have to take off the plate on the back of the hvac unit, there are little clips on the top and the bottom. Just pull up on both sides of the hvac and pull it out.After you take of the black plate, you'll see the brown board underneath. There will be three white clips. Use pliers to pinch them and pull the board towards you.After you get the brown board out of the way, you'll see a green board. This is the board with the lights. Two of them you can see, and the last (the fan control light) is covered by the black fan control unit.That’s the fan control light. To get to the fan control light, you'll have to pull out the fan control unit.First you have to pop off the fan control knob. Stick a screwdriver as far as it'll go and pry it off (it'll shoot off and go flying across the room so watch out )what it looks like with the knob off. To pull the fan control unit out, you'll have to pull up clips on the top and the bottom, while prying it out on the side. This is the top side.On the bottom there are two more clips, pull these up while prying the side.After you get the fan control unit out, you'll be able to pull out the bulb.That’s the fan control unit out.To get all three bulbs out, turn them counter clockwise a bit untill they get loose, and then pull them out.Go get some replacement bulbs. I got these at the SourceCC (Radioshack)These ones are 12V 60mA micro bulbs.Get the bulb out by undoing and unraveling the little wire ends of the bulb. After pulling them straight, u can pull the bulb out. (look at the way the wire is curled so you'll know how to put the new one in. you'll see what to do when u look at it.) Test them with the ultimeter to see if there is any continuity through the bulbs, just to make sure they are blown. put the new one in curl the contacts around like it was before. Put the bulbs back and turn them clockwise to tighten them. Put everything back together by doing the reverse of what you did to take them out. Put The hvac back in and pray that the lights go on. Test to see if the dimmer works with them.
Here is what they should look like when every things said and done. I took off the blue condoms on them because I don’t like the green look they give off.
Enjoy your new lights!
Modified by s14_240sx at 2:30 PM 3/24/2007