Another HVAC LED thread with pics for those interested

[JSvert240sx]

Since I've kinda been scattering random pictures around this forum of the LED mod i did the other day and have received some interest from fellow members, I figured I'd just post a quick how-to that should compliment Attwater's. His instructions helped me, and I made sure to take a decent amoutn of pictures while doing it.

I purchased the LED's at Advanced AutoParts, but most auto stores should have them. A 4 pack of the LEDs that come prewired with a resistor cost $8.

First thing to do is to remove the HVAC unit. to do this you must first remove the radio below it then after removing the 4 screws securing it, you can turn it and fit it through the hole after removing the 3 harnesses attached to the back.

There is also a metal wire that connects to the back of this that adjusts the heatercore I'm assuming when u adjust the hot/cold slider. to remove this I just used some needle nose pliers to twist it out since it's got a hook on the end.The slider knobs need to be removed first, they should pull right off, but u may need a screwdriver for a little leverage.

By pressing these two tabs in on either side the entire HVAC unit should pull apart into two pieces.(there are good instructions for disassembling the HVAC in the FSM, but this is essentially all there is to it.

The bulbs can technically be removed without pulling this all apart and soldered in, but it give you a good chance to clean some dust out of there and also to check the clearence for the LED's since there isn't too much room.

The two bulbs are located under that clear plastic panel sitting behind the HVAC in that picture.

With the two bulbs removed and the unit flipped over you can see where the LED's much be inserted and soldered to.

Here is the LED after i cut a significant amount of the wire to shorten it to close to the size of the bulb.

Insert the two LEDs in the same position as the original with one wire on each side of the whole and solder it in place making sure that the two wires and solders dont touch one another. Please pardon the sloppy soldering, I was using a 40 year old iron and thats the best precision I could come up with, lol.

Here's a view of the LED's after they've been soldered in place.

Put everything back together, plug the HVAC back in and don't forget the metal wire that attaches to the back and it should look like this:

[fallingspeaker]

Sorry can't see the pics (don't know if this is true for everyone or just me at work). Why not try to host them on Nico site itself instead of photobucket?

[JSvert240sx]

I'm at work and can see them fine... wonder if everyone else can see them?how do you host them on this site?

[donmeca2020]

looks damn good JSvert, is there a way to change the green also? and would you say this is a pita job?

[JSvert240sx]

looks damn good JSvert, is there a way to change the green also? and would you say this is a pita job?

The sliders that glow green have a weird tiny green bulb in them that I've never seen before... It may be possible to replace it somehow but it would be alot of work.

The job was pretty easy and really straight forward, I recommend it to anyone that has a burnt out bulb or wants a change from the dull color it has stock.

[jonesbplayer]

I cant get my led's to work. anyone know what may be the problem?

[JSvert240sx]

Does it matter which way the LEDs are wired? I had one of mine one way and it didnt work, so i turned it around and it worked fine... also make sure the solder or wires arent touching one another...

[240SX@MD]

Does it matter which way the LEDs are wired? I had one of mine one way and it didnt work, so i turned it around and it worked fine... also make sure the solder or wires arent touching one another...

Yeah, it does, LEDs are diodes. And they only work one way, they allow current to flow in one direction only. I don't remember much from my class, tough. But as you said if they don't work one way flip them. I can check back on how to identify which way os the flow, so they are installed correctly the first time.

It looks really good, i am going to do it on mine, since the bulbs stop lighting up a few weeks ago.

Great info, keep it up.

[adrianfromthecastle]

hey, thanks man, i found something to do this weekend..!

[TurboChargedSE-R]

I did this last night, and really appreciate the write-up and photos. Very easy to do.

[NISXAN]

Or you can just do what I did (hehe)!

The pics really speak for themselves, I guess....





And before anyone asks... yes it works and yes I have A/C...

HUGE thanks to these threads for hooking a brother up!

zer...age=1

and especially

zer...age=1

Just had to share the new pimpness with everyone!

[attwater]

I commend Nisxan for his install. That is not an easy job and it requires a rather odd assortment of parts. Great job! For those of you attempting my LED retrofit, here is a tip:The 2 negative leads for soldering the LED's are all the way towards the front face of the HVAC unit and the other is all the way towards the back. The 2 positives are the leads that meet in the middle. Enjoy and keep the pics coming. I would like to see someone try a color other than blue.Best of luck
Modified by attwater at 4:46 PM 6/12/2006

[0wn3r]

This does not apply to S14's.

I may have made a thread somewhere about how mine was broken... well i just stuck in a tiny allen wrench and moved the board and it came back on (after several attempts) it's working again... for now.

Anyways, good luck trying this on an S14 hvac unit. You'll be there for a good hour or more. [and cross your fingers that you don't break anything along the way]

[~4N~]

Sorry for digging this thread up, but can you also change the bulbs inside the buttons, and the bulbs inside the adjusting knobs?Also, are they #74 bulbs?Thanks for any info.

[ishkabibble]

NISXAN, do you have pics of your complete interior posted somewhere? It looks pretty nice with the red.

[JSvert240sx]

Sorry for digging this thread up, but can you also change the bulbs inside the buttons, and the bulbs inside the adjusting knobs?Also, are they #74 bulbs?Thanks for any info.

The bulbs used in the buttons are something I've never seen before so I didn't really bother investigating them much. They were a weird square shape with two pins that plug into the switch.

[corey240]

dude thank you! thes are the only bulbs in my interior i was worried about not being able to change. im making them all amber but i cant find any interior lights like the gauge cluster bulbs. awsome write up, when i swap mine over il do the same stuff but for an s14 and post it up.

[sledrick]

There is also a metal wire that connects to the back of this that adjusts the heatercore I'm assuming when u adjust the hot/cold slider. to remove this I just used some needle nose pliers to twist it out since it's got a hook on the end.

I am having soo many troubles getting this damn hook out! anyone know an easyer way?

[S-13]

the hook is shaped like an "L" threaded through a hole on your lever slider. To remove it there should be a very small e-clip press fitted to keep the straw in place that houses the wire. The needle nose pliers should make short work of it, although I would be very careful as to not lose the clip after trying to yank it out of place since your gona want to re-use it afterwards. I recently replaced mine using really small high intensity super white LED's using the factory housing since i didnt wana solder it permanently like that.

As per the other question about the button lights on the hvac. JSvert is right, they are small rectangular LED's already in there. IMO I think its far too much work to not only get to them without cracking anything, and once you do get it in there it would require a LOT of custom fabrication to somehow wire up a circular shaped LED into a rectangular slot. Once I found out they were LED as well I called it a day. So now every light in my car runs on LED's both interior and exterior(not counting the headlights of course). the only one i couldnt find a size for are for my rear license plate and the little light bulb behind the am/fm tuner.

[My RB25]

I apologize in advance for brining this back up, but do you need LEDs with the resistor build in?

I just bought straight LEDs, just the diode and two wires coming out. I soldered em in (praying the whole time they were gonna be bright enough) and now I have no light in the hvac unit (The fan and temp slider lights work, I didn't check if the buttons did, I got discouraged when I saw no red glow). I'm gonna switch em around, maybe I have em in wrong. Do both those lights work in a series or parallel circuit?

I find it hard to believe I put both of them in backwards. Please let me know before I pull em out, put em back in, only to find out I need the resistor.

[240zac]

looks great.my only question is:

can you do this with white LEDs?

the blue doesnt seem like the light isnt that brilliant. if i were to do blue, i would want it to match my stereo head unit which has some briliant blue (not all that bright) and some white backlighting

[My RB25]

LEDs come in all different colors, they even have some that alternate between three colors. When I was at the store today picking up my stuff I saw red, green, blue, yellow, white and the alternating one.

I'm going to take my HVAC unit apart now and put the bulbs back in, plug in just the board and see if the lights work, I wanna make sure I didn't short anything out. If they work, I'm reversing the LEDs, I'll report back with hopefully good news.

[My RB25]

:::sigh:::

So I called a junkyard today to find a new HVAC unit (You know it's gonna be good when it starts off with that...). I'm going this Saturday to pick it up for $40.

I've been working on cars for 2 years now, never really got into soldering much. Basically I burnt the contacts for the bulb/LED. I looked on the back of the soldering iron package I bought yesterday. They say when soldering onto printed circuit boards you should use a 15v or lower iron...I bought a 25v one. 25v's are used for chassis and sheet metal soldering...

The regular bulbs didnt work, nor do the LEDs that are currently soldered into place. So today I bought two more LEDs and a 12v soldering iron. Then my boss came up with such an ingenious idea, so simple, that can save quiet some time and money. When I get the new unit on Sat. if this idea works, I'll post up a nice how-to. Not trying to blow this one outta the water, but believe me it's A LOT easier if it works. If not, then that new 12v soldering iron is gonna get heated up. I also have a few tips on how to make this install go a little smoother. As I said, when Saturday comes, we'll see.

[S-13]

most LED's will burn out prematurely if your running 11-12V through them. Yes you will need a resistor OR for most aftermarket auto LED upgrades, they will already come with built in resistors designed from a 12V power source.

Also, like you mentioned about your soldering iron, depending on the distance from the soldering point to the LED itself, If the LED is too close to the heat source you could destroy it from the heat generated from soldering

[My RB25]

Well I'd rather burn out a $3 LED than destroy ANOTHER HVAC circuit board lol. But if all goes well on Saturday, I won't have to even solder anything in.

If I burn it out, then I go to another store and find an LED with a built in resistor, because the electronics store I went to has just straight LEDs, the diode and the cathode/anode (two wires coming out the bottom). So we'll see... But does the circuit for the bulbs run 12v through it or does it work off a 5v refrence? 12v seems like a lot of voltage for the tiny halogen bulbs in there. I guess I could hook up my DVOM, but seems like to much work lol.

[ZiG]

Are those 3mm leds or 5mm?

[My RB25]

Off the top of my head I'm not sure. I didn't make it to the junkyard this weekend, I worked to late. Not sure when I'll get there. I might try to see if I can locate another unit at a closer junkyard, the other one is a tad to far. Either that or I'll follow suit and throw that beautiful updated digital climate control unit in. Just gotta see what it entails.

[ZiG]

Ok, so I tried it with a pair of 10mm LEDs I had laying around and it didn't look so good. So I said screw it and modified the clear plastic thing to fit a pair of 194 bulbs. It sure does get bright now.

[reborn240]

I would like to put some LED's in my S14 but those puppies were to big for the holes! (story of my life....) anyway, if i take all the circuit boards out, then put the bulb in from the other side and soder it in place, will that work??? I am also wondering about the voltage difference, would this cause them to burn out quickly, or is the some sort of convertor. And is this the same process for the gauge cluster?? any input would be cool.

[1sikS13]

i would assume no difference being that the max voltage for the leds from advanced auto parts is 12v and most of the electrical in your car is that or less..besides if for some reason you do have a voltage spike..it will not blow that led....12Volts is just a constant recommended power......you can take a 5v led from radio shack and hold it on a 9v battery for a long time and it dont blow out.....try it its only 5 dollars and maybe 20 minutes of your time