Disclaimer: I will take no responsibility to any damage you could have done to your car by attempting this mod. Only people who have at least some electrical background and soldering skills should attempt this. Doing things incorrectly and not carefully will likely damage your climate control unit and other components. I have tried my best to write each steps as into details as possible. If something needs clarification or you have any questions or even you find a mistake in this writeup, please let me know.

Reference: http://www.z3d.com/maxima/blueclimate.html by Zach.

The only thing I did different from the post in the "4th gen how to's" is the way I get power for LEDs
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The bulbs were blown probably during the installation of my new radio. Only the buttons circled by red could be lit. The green-marked ones didn’t work. (see picture below)



So I took off the climate control unit. You don’t have to take off the front piece unless you want to do a white-color LCD display mod. I tried, and then decided not to.



Took off the back piece by releasing a few clips all around the unit. After you took the back off, you should see four bulbs supported by some brown holders to be fixed on the circuit board. Notice that they are all powered directly from the copper pads underneath them on the board. I took them off by simply turning them a bit. It was easy for them to come off. Be careful; don’t damage any of the components on the board by accident. You should see four holes on the board where the bulbs were located.



One of the bulbs in the picture has been replaced with a LED.



Notice that you could change the color of each button by using different colors of LEDs, like what Kevlo911 did (http://forums.maxima.org/showthread.php?t=508451). If you separate the circuit board from the housing, you would be some plastic structures that define which LED’s light goes where. I tried cutting the LED, polishing the LED, and trimming the LED to prevent hot spot, then I found polishing the whole surface actually turned out the best. I used pliers and sandpaper to trim the LEDs in order to fit in to the board and emit light not directionally. I used 5mm LEDs.

 

I soldered a resister (560ohm, 1/2W) to the positive (longer pin) of each LED (white, 5mm, Vf=3.2-3.6V, current max around 25mA, bought from eBay), and a black wire to the negative (shorter pin). I tried to use a bit higher resistor, 560, instead of 470, to bring down the current a bit. Since this is a rated 10000mcd LED, by lowering the current I could make the LED life longer and not too bright. I measured the current when I put 4 LEDs with resistors in parallel, the total current they pulled was ~64mA.
(I tested one of the bulbs with 12V, it pulled 76mA, higher than 4 LEDs combined)



How to get the power? Several options available:
1. cigarette lighter (Zach did so), the climate control will be lit up wherever you drive.
2. ashtray light, nobody I know has tried, I think it should hold. But it’s too far away from the climate control unit.
3. the original climate control wires, so the climate control will be lit only when you turn the lights on, a suggestion from gen4maxima 536, http://forums.maxima.org/showthread....05#post5480105
4. radio? not too good of an idea

So I took option 3. Since the original bulbs were pulling much higher current (maybe 76*4 mA), so the wires should hold. I took off the board, hunted down which pins on the connectors were used to power up bulbs. Also, again, to make sure they were connected in parallel. Actually these four bulbs were connected in parallel with some other components. So I didn’t try to get power directly from the board in the same way the original bulbs did. (Though that should still be ok)




Put the LEDs with brown holders in. I followed Zach’s writeup by adding a piece of paper in between in order for the holders to be tightened to the board. Don’t use anything conductive to do so, or you will have short circuits and burn off something for sure.
Put the front and back pieces back together. Connect the red wires (positive with a resistor) of 4 LEDs together, and do the same thing to black wires (negative). Make sure you cover up all exposed wires good to prevent any short circuit. Very important, make sure the positive and negative pins of each LEDs don't have a short circuit (touched) after you pull them around to connect the wires. (I used those heat-shrink tubes and electrical tapes to prevent short circuits.)



Hint: I actually checked to see if any LED is burned up after each step by applying 12V across the LED and resistor. So that I would not have a dead one after I put everything together.

 

Since we have already known which two pins of the connector on the board supplies the power. I went to the car, double-check it from the car end using a multimeter to know the polarities of the power when headlight is on. LEDs are polarity-sensitive. I marked the polarities on the connector by a marker.
The sky-blue wire actually is positive (probably a dimmer wire), and I tap it with my red wire with a quick connector. I differentiate it from the other with a black electrical tape on the quick connector.
The red wire (with silver stripes) at the car end is actually negative, so I tap it with my black wire. Again, make sure the polarity is connected correctly. You could turn on the headlight to check if it works. (I got real nervous here).



Great, you are almost there. Put them in, make sure the wires are secured, not in the way of air or anything else.



And the result when it’s dark.



(I changed my Hazard/Rear Defroster lights according to http://www.petah.org/maxima/hazard.htm)

 

Looks great man! Very nice work and awesome write-up.

 

very very nice install great pics

 

Good write up. Looks nice, still looks like some hotspots.

 

Awesome write-up, thanks!