How-To: HVAC RGB Upgrade (pics & video)

[neurotictim]

Okay, so I had a lot of response to this on one of the Facebook 4Runner groups, and I’ve finally found time to do a write up. This is not a difficult mod to do, it just requires patience and a reasonably steady hand with a soldering iron.

First thing you should know: If you do this, you will not be able to put normal light bulbs back in, as this mod requires permanent modification to the boards of the switches.

Second: These lights are wired to be “on” when the parking lights or headlights are on. This means that the LCD and switches will NOT be lit with the exterior lights off, and that’s how I wanted it. To do any more than this would require a lot more time and engineering than I wanted to put into this project, but you are welcome to jump off from here if you want. I feel like having the backlighting on when it’s bright outside is pointless anyway, but ymmv.

Third: This is an afternoon project, but plan for extra time because it’s always a good idea, and your 4Runner will be out of commission while you’ve got the HVAC out. Don’t try to start the truck without the HVAC plugged in – since the airbag indicator is located in the HVAC assembly, there’s a possibility starting it while unplugged will trip the airbag light, which (to my knowledge) has to be reset at the dealership.

Disclaimer: This writeup is intended as a guideline for modifying interior lights so that they are RGB LED driven. I am not claiming anything more than that this is the process I used, shortened for brevity, and that results may vary. Don’t blame me if you burn yourself, get flux in your eyes, etc., and don’t blame me if it doesn’t turn out exactly right the first time.

Things you’ll need:

Soldering iron / solder / flux and solder wick strongly recommended / heat shrink (especially small)
Screwdrivers / Dremel / black paint / cloth or electrical tape recommended

You’re going to need to order a few parts online.

First, you’ll need an RGB controller of some sort. Whether it’s IR remote controlled or via Bluetooth/WiFi, it needs to be 12v driven. I’ve used both of these and they work well.

https://www.amazon.com/gp/product/B01JS0KEBW/ - Wifi/App controlled

https://www.amazon.com/gp/product/B00AF5YOK2/ - IR remote, no app.

Second, you’ll need some LEDs and wire.

https://www.amazon.com/gp/product/B07FDW4M89/ - You won’t use 100 feet, but it’s nice to have on hand.

https://www.amazon.com/gp/product/B0777BQC1P/ - These aren’t strictly necessary, but nice to have handy as well.

https://www.amazon.com/gp/product/B01AUI4VR4/ - These are the LEDs I used to replace the orange triangle lights in the switches. I used white, but you could theoretically use any color you can want, as long as it’s 3mm. These are 3V and work just fine.

https://www.amazon.com/gp/product/B01C19ENFK/ - These are the RGB LEDs used to light up the rest. Note that they’re common anode, that’ll be important when we wire em up.

https://www.amazon.com/gp/product/B06Y5GC3VY/ - These are the resistors that regulate the voltage to the LEDs. I bought a big variety pack, but really you only need the 100 ohm, 150 ohm, and 180 ohm resistors, at 1W power. If you buy a variety pack you can experiment, but make sure they’re at least 1W rated.

https://www.amazon.com/UTP-Circuit-Adapter-Circuit-Accessories/dp/B07FKWRV48/ - Always handy to have fuse taps around.

https://www.amazon.com/gp/product/B079RBL339/ - when you’re DIYing 12V projects, these are always a good thing to have on hand.

Step-By-Step

Start off by pulling the HVAC panel out. It’s super simple – remove the cubbie thing by opening and then pulling up on it, remove the 10mm bolt from the bottom of the HVAC panel, and pull it out.



Now you have the HVAC panel free, unplug the one plug in the back and take it to your work area.

We’re gonna pull the lights first off. Just take a flathead screwdriver and give them a counterclockwise twist, they’ll come right out.



Next we’ll remove some screws. The top part will flip up, and the cover on the bottom cover piece will lift right off.



Now we’ve got that stuff open, time for a little test solder. Unscrew these two screws:



Flip it over and you’ll see the LEDs. Go ahead and heat up your soldering iron, use your solder wick and flux, then go ahead and swap out those LEDs for a pair from what you bought online. Pay attention to the polarity of the LEDs. Look close at the LEDs before you replace them, make sure the new ones are oriented the same.



Now that you’re warmed up on soldering, we’re gonna pull apart the switches and replace those LEDs. This part is tricky only because the pads (copper runs with holes for the LEDs) tend to lift if they get even a little too much heat.

REMEMBER: Use only as much heat as you need, and apply it only as long as you need to.

These switches come out surprisingly easily. Lift up on the ribbon cable holder catches. Be careful at this point, just use a screwdriver blade and sort of pull directly up. Do each side, then gently pull the ribbon cable free.



Then it’s just one screw each (in purple), and then you just have to squeeze these little posts (circled in green), and out pops each switch.



On the back of each switch there are three screws. Go ahead and remove these to get to the circuit board inside.



Once you’ve unclipped the circuit boards, you’ll see that the LEDs are clearly labeled on both sides. Just like with the recirc/defrost button LEDs, you’ll use solder wick and flux to remove and replace the existing LEDs. Pay attention to polarity!



Now, do that again about a dozen times or so. These LEDs will be super bright when the parking lights/headlights are off, so fair warning, you may want to dab a little black paint on the top of the dome to lessen their brightness. They WILL dim when you turn lights on.

**THIS IS THE DO OR DIE PART**

This next step will ruin the switch, at least as far as OEM lighting. If you’re not comfortable with that, go ahead and reassemble everything.

Still here? Awesome.

Use your Dremel and a suitable bit (I use the cone grind stone bit) to widen the hole where the light bulb normally goes. It needs to be big enough for your RGB LED to pass through without getting hung up. Should look something like this when it’s correct:



Now, do this for all three switches. Once that’s done, go ahead and replace the circuit board in the backing, but don’t reassemble the switch just yet. One more step.



If you look into the other half of the switch, you’ll see where the light bulb normally goes, and how there’s a clear plastic ring inset. This allows the light from one bulb to light up all the different sections of the switch, but for our purposes we need to darken it a bit. So you’re going to take some paint on a small brush – I used my touch up paint, kind of like a fingernail polish brush – to drop some black paint in there. You’ll see what I mean when you look. You’re welcome to take this half apart – there’s a screw underneath the front cover, but it’s a real pain to get off without scratching it to hell – but you don’t need to. Just carefully lower the brush down until you get resistance.



Let that dry and you can reassemble the switches, and even replace them in the panel.

 

[neurotictim]

RGB LIGHTING

First things first, take one of your RGB LEDs and put it in a clamp or holder of some sort so that the leads are pointed up. Time to do some work. First things first, take your tiny heat shrink and cut it so that you leave only a little bit of lead on each leg.

From left to right – bare LED, leads are as follows:
Blue
Green
Power
Red

Note that the power lead is longer than the rest. That’s how you know which is which. Normally you would cut these leads short, but we need the stiffness they provide, so just slip some small heatshrink over the leads, leaving enough to solder wire to the tips.



You’re going to do up eight LEDs with that heatshrink that leaves the leads exposed, then it’s time to arrange them.

Put the covers back on, both the upper half (covering the big circuit board) and the smaller one at the bottom. Make sure you use the correct screws.



The three holes circled in red will be very snug fits for your RGB LEDs. You can press them in, or you can use your Dremel to open up the holes a teensy bit and then use a dab of hot glue to hold them in place.

The five yellow holes is what we’re gonna focus on. The LEDs will not just fit, they’ll pass through. And that’s what you want. In the case of the switches, you want to insert them as far as you can, till they rest against the plastic that you painted a little while ago. The leads should be poking up out of the hole.

With the two LEDs that go in to light the LCD screen, you’re going to have to play with them, so just sort of arrange them loosely.
Next – and you’re getting close, now! – is to wire them. This is where all that wire will come in handy. Take your time, strip and tin the wires, and run from one LED to the next, building your own harness. In the end, the harness should terminate in one red, one green, one blue, and one black wire. Just leave the ends exposed, we’re not quite done here.

Unfortunately, I didn’t take pictures between building the harness and wrapping it, but when you’re done it should look something like this:





DO NOT APPLY POWER TO ANYTHING YET!!!

Couple of important things to do first.

Number one, you’re going to want to dab some black paint on the end of a few of these LEDs, in particular on the ones that fit snugly in the pic above. Most of the light from these are focused through the end, but as close as they are to the buttons, you’ll notice the individual colors when you try to blend or make white. A couple of coats helps – but doesn’t eliminate – this problem.



Number two, we need to talk about resistors. Long story short, without these, your LEDs will burn out. There’s some basic math to do here, using Ohm’s Law, and you’re welcome to look it up… Or you can just trust me and go with the resistors I recommend. Unfortunately, like with the harness, I didn’t get a good picture, but the long and short of it is that you’re going to solder a resistor in line with each of your color wires coming from your harness.

I apologize for the quality of this pic, but it’s the only one I have that shows what I’m talking about.



You’re going to attach the 100 ohm to red, the 150 ohm to green, and the 180 ohm to blue. Because the perceived brightness of each color is different at the same voltage, the goal here is to have it LOOK more or less the same level of brightness by adding resistance and dropping voltage across the resistors.

Anyway, use the RGB wire to the other side of the resistors, and just attach the power wire straight through with no resistor. Use one of these if you got them.



Now you’re ready to apply power and verify that you got all your lights working. Hook up the controller, whichever one you’ve got, to a 12V power source, and then plug in your harness.

Assuming it works – and hopefully this writeup made it pretty easy – now all you have to do is mount the lights. This isn’t super difficult, fortunately. You’re going to wedge the three into their spots, and/or hot glue them in, without much difficulty. Insert the switch illumination LEDs – as far as they’ll go, and bend the wires so that you know how it’s supposed to look.

NOTE: The resistors, in particular the 100 ohm resistor on the Red line, will get hot. That’s a side effect of dropping voltage, and is literally impossible to prevent. During the testing phase of this project, I let the lights running for a solid 24 hours without any problems. I actually burned up some ¼ watt resistors in this process before I settled on 1 watt, but just so you are aware, they DO get hot to the touch.

As for the LCD backlight LEDs, well… All I can say is that you’re going to have to play with them to get them to light the display more or less evenly. It’s hard to describe, but there are pieces of cardboard on the back of the LCD that keeps the lights from shining direct; you have to screw with them to get them right, but once you do, you’ll know it.



After you’ve gotten them where you want ‘em, use hot glue again, or some other reasonably removable adhesive, to keep them in place. I wrapped my wiring in cloth tape, then used the hook side of some self-adhesive Velcro to hold it in place, but to each their own.


Now all that’s left is installing!

INSTALLATION

This is without a doubt the easiest electronic install ever. Since we want these to be on when the running lights and/or headlights are on, we’re just gonna run a fuse tap from the taillights fuse, and find any good metal ground to ground it with a self-tapping screw.



Run the wires into the console, plug into your RGB controller, and then stuff it all back there, using zip ties to keep it neat and orderly. I highly recommend either ordering some 12V DC power connectors (see above) or cutting a center positive connector from a handy power cord in your junk cable collection (we all have one, it’s okay).



Now put your HVAC control back in and verify it works! If you’re using a WiFi or Bluetooth controller, you’re done. If you’re using a controller (as I did until I got my WiFi controller in), you can drill a hole in the trim piece just above where the pop-out pocket slims down, and poke the IR receiver down through there.



You can only change colors and stuff with the pocket open, but it’s better hidden than a hole in the dash, lol.



Anyway, that pretty much sums it up. I blew out a half dozen LEDs, wasted a ton of wire, and in general made about a bazillion mistakes in the process of doing this, but hopefully a thoroughly done writeup will prevent others from making the same mistakes. Good luck!

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[rokr1292]

This is awesome, OP. Great job.

 

[tv4184]

Thanks for this. Brings the truck into the 2010 era for sure.

 

[4RunnerIdiot]

It's probably less clean, but couldn't you skip the resistors if you put the right voltage into the controller? I don't see an option for USB power on the controllers you linked, but the LED controller I have has one. I'd probably use something like this:

https://amazon.com/HOMREE-Converter...f=sr_1_4?s=electronics&ie=UTF8&qid=1539873942

Or without a USB power option:

https://amazon.com/DROK-Converter-S..._bxgy_img_3?_encoding=UTF8&pd_rd_i=B00C63TLCC

 

[CookieRoe]

Holy Crap!

Very nice, I would've done the reverse polarity thing, but wow, GREAT JOB!

This should be included in darkie's LED thread.

 

[neurotictim]

It's probably less clean, but couldn't you skip the resistors if you put the right voltage into the controller?

The resistors aren't for power to the controller - it's a standard RGB controller you can buy with any kit from Pep Boys/Autozone/Advance/Amazon/etc. They all run on 12V.

The resistors go between the RGB LEDs and the controller; by and large, the commonly available controllers use a 12v hot circuit to power the LED strips, with ground applied selectively for colors. What I've done here is essentially used 5mm RGB single LEDs in place of the Smd RGB strips you can buy anywhere. If you run RGB LEDs direct from the output of the controller to the LED, it's gonna flash once and burn out. Trust me, I did it accidentally and had to rewire all 8 LEDs.

I wanted to use these readily available controllers because doing so is easier than reinventing the wheel, so to speak. You could absolutely do all this without the resistors by using a Raspberry Pi or some other controller to accomplish the same end, but it would take a lot more time and effort than I believe necessary to achieve the same result.

You could also use lower wattage resistors by running the LEDs in parallel in smaller groups, then tying them to the connector, but I was going for relative simplicity.

 

[4RunnerIdiot]

The resistors aren't for power to the controller - it's a standard RGB controller you can buy with any kit from Pep Boys/Autozone/Advance/Amazon/etc. They all run on 12V.

The resistors go between the RGB LEDs and the controller; by and large, the commonly available controllers use a 12v hot circuit to power the LED strips, with ground applied selectively for colors. What I've done here is essentially used 5mm RGB single LEDs in place of the Smd RGB strips you can buy anywhere. If you run RGB LEDs direct from the output of the controller to the LED, it's gonna flash once and burn out. Trust me, I did it accidentally and had to rewire all 8 LEDs.

I wanted to use these readily available controllers because doing so is easier than reinventing the wheel, so to speak. You could absolutely do all this without the resistors by using a Raspberry Pi or some other controller to accomplish the same end, but it would take a lot more time and effort than I believe necessary to achieve the same result.

You could also use lower wattage resistors by running the LEDs in parallel in smaller groups, then tying them to the connector, but I was going for relative simplicity.

As far as I know, these generic controllers are designed to run on a variety of voltage inputs, and will output whatever you put into it. So putting the right voltage into the controller for the LEDs will output the right voltage for the LEDs, and the controller will be happy. The controller I have says it takes 5v to 24v, and my LEDs are 5v, so everything is happy as long as the power to the controller is 5v.

 

[neurotictim]

As far as I know, these generic controllers are designed to run on a variety of voltage inputs, and will output whatever you put into it. So putting the right voltage into the controller for the LEDs will output the right voltage for the LEDs, and the controller will be happy. The controller I have says it takes 5v to 24v, and my LEDs are 5v, so everything is happy as long as the power to the controller is 5v.

I hadn't heard this before! Never even occurred to me to try to put anything other than 12v on em, lol. When I have time I'll give it a whirl - I've got plenty of power supplies - and see what happens. Thanks dude.