DIY: MKIV Late Model LED Dash Conversion (Idiot's Guide)

[Soup_TT]

Hey Everyone,

I've learnt so much from the forums (SF) and spent so much time on here, that I figured I may as well try to give something back. I couldn't really find an "Idiots Guide" for converting the stock LED / Bulbs on the Supra's Dash to better quality, brighter, different colour LED's so I decided to do my own write-up. Bear in mind that this was my first time doing any electrical work on the Supra and I've never soldered in my life. It took me a while to take everything in, regarding LED's, soldering, resistors, diodes, etc, so hopefully I can dumb it down and make it easier for you.

Everything in the DIY relates to the Series 2 Dash, I will try and include relevant information about the Series 1 Dash where I can.

DISCLAIMER

Even though I'm doing this write-up so people can attempt to do it themselves, I will not accept any responsibility if something goes wrong, or you stuff up. You are doing this modification at your own risk, and provided you take all the necessary precautions, you should be fine! But don't hold me liable if you screw up your dash, and need to pay Toyota an odd $400 for a new one! This modification can take time to do, especially if it's your first time, so it's great if you can get your hands on a spare A/C Panel so your car isn't off the road for too long.

THANKS GOES TO

Jason for his thread and answering quite a few PM's initially http://www.supraforums.com.au/forum/...ead.php?t=7936

michaelvanle from the US Supraforums for his thread here http://www.supraforums.com/forum/showthread.php?t=388487

Simon for his website over here http://internetwork.org.uk/led_guide/led.htm

LED CONVERSIONS COVERED

You can go overboard and change everything to LED inside / outside of your car if you like. I did all the ones I could reach with the Dash pulled off!

1. Late Model Instrument Cluster (i.e. Speedo, Tacho, Boost, Temp, Fuel Gauges)
2. A/C Panel (Fan Speed, Climate Control, Buttons, Indicators)
3. Ignition Ring
4. Astray Light
5. Rear License Plate Lights
6. Analog Clock

LED's & OTHER PARTS REQUIRED

Ok, the big question... Where do i get my LED's from....? Being a proud supporter of the US Economy ( ). I got all LED's from www.superbrightleds.com. They were fast, efficient, reasonably priced, and I didn't have a single dodgy LED. At the end of the day, you always get what you pay for. If you want to jump on eGay and buy them off some dude in HK thats fine, but you have no idea about the quality etc. Jason (SF.com.au Member), had some eGay LED's in his writeup and you can see where they have started to yellow! Pay the extra couple of bucks and get them from superbright.

Superbright have two shipping options. They have $30 Trackable Shipping and a $5 Air Mail. I've tried both. The trackable shipping arrived within 1 week, and the Air Mail one took a few more days to come. Both are fine. Unless you're ordering more than $100 worth of LED's, you should be ok with the $5 shipping option.

1. Late Model Instrument Cluster (i.e. Speedo, Tacho, Boost, Temp, Fuel Gauges)

4 x 194 Type WLED-x5 LED Wedge Base Bulbs (Disperses Light Evenly)

You can choose what colour you want to have, I've put some pictures of the different combinations. I found white to be the best, because you can clearly see the Redline area on the Tacho, Blue wasn't too bad, and red looked ok as well. It's easy to swap them over, so if you want, order 4 of each colour combination.

2. A/C Panel (Fan Speed, Climate Control, Buttons, Indicators)

This is the most difficult part of the whole conversion, due to soldering, calculating resistor values, etc. I'll try to cover as much as I can. First up the LED's themselves.

If you have a look here: - http://www.superbrightleds.com/leds.htm, you'll see a whole bunch of LED's that you can get. I used only 3mm LED's, you can get the 5mm ones, but there's going to be a lot more work, trying to get them to fit. 3mm light it up fine, no need to go to 5mm IMO.

MCD Ratings are important. They refer to the actual brightness of the LED themselves. The higher the MCD Value, the brighter the LED. Go for the highest in the 3mm ones.

The wider the viewing angle, the wider the dispersion of light. Again, bigger is better. I only ordered white and blue 3mm LED's so I didn't really have much choice there.

IT DOESN'T HURT TO GET A FEW EXTRA, IN CASE YOU STUFF UP, OR GET SOME MORE IDEAS WHERE YOU WANT TO PUT LEDS.

Fan Speed - 7 x RL3-W3030 White / RL3-B2030 Blue 3mm LED

Climate Control - 2 x RL3-W3030 White / RL3-B2030 Blue 3mm LED

AC Panel Indicators - 11 x RL3-W3030 White / RL3-B2030 Blue 3mm LED

AC Panel Buttons - 10 x RL3-W3030 White / RL3-B2030 Blue 3mm LED

Colours are a personal choice. I loved the White / Blue combination and stuck with that on both AC Panels that I did. You might have a different preference. Be creative and post up your results!

1 x Zener Diode 1W 4V7 / 5V6 / 6V2

I'm not going to ramble on and pretend I know about how a Zener Diode work, because I don't. But I know this, the brighter the Zener Diode, the brighter your LED's will be when your headlights are turned on. Again it comes down to personal preference. The stock Zener Diode that you will find on your board will probably be a 4V7 one, or if you have an early model MKIV it will be a 3V9. If you like to be blinded while driving, like me (go for a 6V2 - it's just a tad bit dimmer when the headlights are on). Otherwise the 5V6 isn't a bad option. Best way to find out, buy both and see which one you prefer. They cost around $0.40 from Dick Smith (SUPPORT LOCAL ECONOMY) and if you're after product codes, try 1N4734 (5V6) or 1N4735 (6V2).

1 x 1W 150 ohm Resistor (DSE Code: - R1454)
2 x 1W 180 ohm Resistor (DSE Code: - R1456)
2 x 1W (or 1/2W) 270 ohm Resistor (DSE Code: - 1460)

Resistors are a tricky thing to dwell on if you're a newbie to electronics. The basic idea is that you'll need to create an LED Circuit for lighting up the buttons. If you supply 12Volts directly to an LED, you're going to blow it up. The resistor will limit the amount of current going to an LED or a cluster of LED's. A bit of basic info: -

Input Voltage = ~ 12 V
Output Voltage = ~ 3.6 V (Superbright LED's)
LED Current = ~ 20 mA

If you're not going off on your own tangent, and you're following me, don't worry about the above info, just follow what I did. More about LED Clusters and the like later on with pictures.

3. Ignition Ring

1 x 74 Wedge Base LED bulb

Again choose whatever colour you want.

4. Astray Light

1 x 74 Wedge Base LED bulb

Same as above. Getting easy now isn't it..???

5. Rear License Plate Lights

2 x 194 Type WLED-x5 LED Wedge Base Bulbs

Same as the ones used for the Instrument cluster. I think white looked the best out of all them.

6. Analog Clock

2 x 74 Wedge Base LED bulb

See further down for pictures, I think either Blue or Red looks best!

7. Other Parts Required

1 x Soldering Iron and Solder Wire (including Flux).

I got a 40W Soldering Iron from JayCar and some solder to go along with it.

1 x Multimeter

A Multimeter will save you hours of frustration when things aren't working (trust me, not everything works first time). I got one from JayCar for around $50, but it does a heap of other stuff. You can get ones as cheap as $10. Try to get one which will show you voltage, current, as well as do a continuity test!

Miscellaneous Tools

General stuff you should have around the house like a file, duct tape, pliers, scissors, etc.

PROCESS FOR LED DASH CONVERSION

Ok, now that all the theory is over, lets get into it. First things first, make sure you disconnect the negative terminal on your battery!

Removing Dash Components

Using a Phillips head screwdriver, unscrew the top of the dash panels by unscrewing the 5 screws pictured.



Once you have unscrewed those 5 screws, you need to pull the top portion of the dash off. Grab onto it from both ends and pull firmly, but be careful not to break any of the clips holding it in place (from behind).

On the left hand side of the top panel that you have just pulled out, there will be two connectors that you will need to unclip. Also, you may as well remove the screw holding the other dash piece in place.



Moving to the right side of the top dash panel, you'll find another connector that needs to be unclipped and also another screw.



You now need to remove the 5 Gauge Face Piece that covers your instrument cluster. This will basically pull out and then you'll need to maneuver it in such a way that you can pull it out completely (over the top of your steering wheel).



Next the panel around your shifter will need to be taken out. There are around 4 clips which are locking it in, so you need to carefully lift up around the edges. I generally try lifting from right of the shifter and around the ashtray area.



Once you have unclipped it and lifted it out a bit, you'll find the ashtray light connector plug which will need to be unplugged so you can remove the panel completely.



Next we need to remove the main panel of the dash. This is where the AC Panel / clock is connected to. We previously removed the screw holding it in place, so pull firmly at the top part of the panel and it should unclip. Do the same down the bottom and then around the side. There are quite a few wires and plugs / connectors running to the back of this dash piece so we'll have to remove them all. Unfortunately I was unable to get all of the connectors in one picture, so you'll have to take my word below about which connectors need to be removed.

[Soup_TT]

Here are all the plugs / connectors that you need to worry about removing when removing the center dash piece.

1. Stock Analog Clock Connector (Top of Panel)
2. 2 x Connectors for the Main AC Panel <- BIG PAIN IN THE ASS. (Middle of Panel)
3. Cigarette Lighter Connector (Just pulls out) (Middle of Panel)
4. Cigarette Lighter Light (Twist and Pull) (Middle of Panel)
5. Traction Control Connector (Down the Bottom of the Panel)
6. Active Spoiler Connector (Down the Bottom of the Panel)



Here's what the interior of your MKIV Supra should look like once it's all been removed. It can be a good idea to put duct tape or some other protective stuff over your head unit so you don't scratch it while you're plugging in your AC Panel for testing later on.

Replacing the Stock Bulb Lights on the Instrument Cluster with LED's.

To remove the instrument cluster, there are 4 screws that need to be undone, and around 3 plugs / connectors on the back of the instrument cluster which need to be removed (Top Section). Be careful when unscrewing these as they can fall down into the inner depts of your dashboard, never to be seen again. Magnetic screwdrivers can be handy here!



Below you can see a view of the back of the Instrument Cluster board. The red circles depict the stock bulbs for lighting up the instrument cluster. Simply twist and pull the bulb holders out, remove the stock bulbs and stick the new ones in place. They are polarized so if you stick them in and find they are not working, spin the bulb holder around. It really comes down to personal preference about which ones looks nice. I've attached some pictures of the ones I've done, I prefer the white out of all of them. Please note, I only had 3 bulbs for each colour (except white) when I took these pictures, so there is no bulb that sits behind the Boost / Temp / Fuel Gauge.



Here are some of the sample ones I did, to help you get an idea about which colour you might like.














Replacing the Stock LEDs / Bulbs on the AC Panel

Ok here we go. This is the tough bit! Lets open up the AC Panel Unit First.

You'll need to unscrew it from the Middle Dash Piece. There are three screws holding it in place. Once you have separated it from the dash, you will find 4 clips on the outside of the AC Panel Unit. Two will be on the top, and the remaining two will be on the bottom. In the picture below I have circled (red) two of the four clips that need to be undone, as well as some screws which need to be removed (yellow) to get to the circuit board. Ignore the resistors in the picture, your stock unit won't have them (these pictures were taken of a unit I had already completed).



Once you remove the back cover, you should seem something looking similar to the image below. Remove the screws that you see (yellow) and also unplug the white connector (red) connecting onto the smaller PCB (Climate Control Controller).



Unhook the smaller PCB from the plastic housing by gently releasing it from the two back clips holding it in place.



BE VERY CAREFUL WITH THE SMALLER PCB AND THE WIRING GOING TO THE MAIN PCB. The first dash cluster I did, I totally screwed up because I moved it around to much (during testing and fitting), that the wires started to split and tracks started lifting etc. So be careful..!!!

Once you push the wires behind, you'll be able to see the stock bulb holders which are used for illuminating the buttons on the A/C Panel. Using a plier, remove all of the stock bulb holders (red). There may also be additional screws that you'll need to remove (yellow). Remove the black back cover and you should be exposed to the rear side of the AC Circuit Board.



From the front of the A/C Panel, remove the Fan Speed & Climate Control knobs (pull off), and remove the nut holding the rotational selector in place.



You should now be able to pull the Circuit Board away from the plastic A/C Panel and be left with something like the below picture.



The front of your A/C Panel will look similar to the below picture. Remove all the plastic components, there will be four in total, i.e. Fan Speed, Climate Control (You need to pull the black plastic dial off the front of the AC Panel Plastic Cover and then remove the white plastic insert), top row of LED's and bottom row of LED's.



If you are having problems taking the plastic parts off, you may need to cut some of the plastic bits that go through the PCB.



Picture of some of the stock plastic components.



You need to modify the stock plastic inserts so they can take the LED's. The two plastic rectangles need their insides "gutted" completely and also it's a good idea to drill the holes where the LED (Indicators) are going, so there are no fitting issues later on. Just open up the little holes a bit more. The circular plastic inserts are more difficult to modify and therefore it's probably best that you have a look at the image to see how you would modify it.



De-solder all the existing LED's from the PCB. Make sure you don't touch a particular solder point for two long otherwise you'll find the tracks will start to lift. I've found the best way to de-solder the stock LED's is to have someone else pull the LED with a plier while you heat up the solder joints from behind with your soldering iron. Some people prefer to cut the legs off and then solder the new LED's on, but I've found it better to just completly remove the LED's and solder the new ones in.



This is what your PCB will look like once you've de-soldered all the LED's.



Now you will need to solder in the new LED's. Again remember not to solder for too long at one point otherwise the tracks will start to lift. Keep in mind that the positive and negative legs of the LED's need to be correct. Generally with LED's the longer leg is the positive. Also if you look inside the LED itself, the smaller one is the anode (i.e. positive side).



In the below picture you can see the Zener Diode circled. It's a good idea to change it so your LED's are equally bright when you switch your headlights on. For more a discussion, see the first section. The Zener Diodes have a black strip on them, so keep it pointing in the same way as the stock Zener Diode.



Once you've gone an soldered all the LED's into place, it's probably a good idea to go and test it, make sure it's all working ok, and there are no problems.

Now for creating the back light illumination for the buttons, we need to create a cluster / parallel circuit of LED's. We need to create: -

1 x 4 Parallel Circuit of LED's for the Top Row of the A/C Panel Buttons + 150 ohm Resistor
2 x 3 Parallel Circuit of LED's for the Bottom Row of the A/C Panel Buttons + 180 ohm Resistor
2 x 2 Parallel Circuit of LED's for the Fan Speed & Climate Control + 270 ohm Resistor

You will need to use the stock bulb holder and fit the LED's and Resistor into that. I've picked up a couple of tips and tricks along the way that I will share with you as we create the LED circuit.

Here is a picture of what a stock bulb holder looks like in the A/C Panel. Even though the bulb holder has already two holes in it, I've found that when you actually lock the bulb holder into place, there is a high risk of the LED Legs touching each other. So, I've put two more holes perpendicular to where the others were, i.e. they pass though the two holes you have on the bottom of the bulb holder. I didn't have any tools for doing this, so I found the best way to do it was to heat up a sharp long needle over the gas stove (hold it with a plier while heating & using it) and once it gets red hot, it was pass through the plastic and make a hole. You may need to do it two or three times to make the hole properly.



Once the holes were punched through, I decided to shave off the bottom bit on the bulb holder because my LED legs weren't long enough to be able to go through the long hole and then loop back around to make contact with the Positive & Negative Terminals on the PCB (more about this later). This is what it looks like:



Also, to ensure that the stock bulb holder locks into position when twisted, I found that I had to shave a bit off the tabs on the side of the bulb holder. You need to keep a little bit of the top portion of the tab, but everything below that you can shave down. Otherwise you might find that with the thick LED legs wrapped around the bulb holder, it's too thick to be able to twist into the board. Although blurry, hopefully this picture will give you an idea about what I'm talking about:



The image below shows the back of a A/C PCB and you can see which ones are the positive contacts for the bulb holders and which ones are negative.

[Soup_TT]

To create the LED Circuit, feed one LED through the bulb holder, check the polarity (i.e. Positive / Negative), and you need to solder the resistor onto the positive leg of the LED. Now wind the extended leg of the LED around, and loop the leg around the sides of the bulb holder (like the stock bulbs) so that when you will twist lock the bulb holder into the PCB the leg will make contact with the positive contact on the PCB. Do the same for the negative, (if it is too short to spin around, then you need to solder another bit of a leg or wire onto the LED leg). The image below clearly shows that, and you can see the looping of the positive leg. In the image I already have a cluster, just ignore that for the time being and focus on the single LED and how it's setup.



Here are some more images, so you can have a better understanding about the legs and the "looping".







Once, you've done the first one, you can try and solder another one in parallel to it and then try to fit it into the stock bulb holder, or the better way would be to do the single LED + Bulb Holder Combo and twist and lock the bulb holder. Then add more LED's as you go!

In the image below, you can see that I've created one stock bulb holder + LED + resistor combo and twisted it into place. I've then bent the legs of the LED, so that it is pointing upwards towards where the button is going to be. Then, I've soldered another LED to the back of it (ENSURE THAT THEY ARE CONNECTED IN PARALLEL, i.e. the positive leg of the LED should be soldered to the positive leg of the LED in front of it).



More LED's soldered together to create a 4 LED Parallel Circuit.



Putting the modified plastic inserts back on.



Now wouldn't be a bad time to go and test and make sure you've got it right. I had no problems plugging the A/C panel back in with my dash completely pulled apart, attaching the negative terminal to the battery and moving the key to the "ACC" position to test. Some of you early model MKIV guys may have an issue of your airbag light coming on etc. I'm not sure, because I haven't done this on an early model. Read up about it, even if you do get your airbag light coming on permanently, there's a writeup on mkiv.com about how to clear that. No big deal. If you test and it doesn't light up: -

1. Check whether the LED Indicators for the A/C Panel are lighting up. They are pretty simple, so you should have got them right.
2. Make sure the Positive & Negative legs of the LED's aren't touching each other in any point. If you used my idea and drilled the two additional holes through the bulb holder, you shouldn't be having this issue.
3. Perform a continuity test (DON'T DO IT WHILE YOU HAVE POWER RUNNING THROUGH THE BOARD), buy putting one multimeter point on a positive point on the circuit board (preferably at another Stock Bulb Contact Point on the PCB), and use the other point on another positive point.
4. Make sure you have the positive side of the LED cluster touching the positive point on the PCB and the same goes for the negative.

In the image below, I've completed the 2 x 3 Parallel LED Circuits for the bottom row of the A/C Panel. Remember to use the correct value resistor.



Creating the Two LED Parallel Circuit. This is designed so that the "HI" & "LOW" of the Fan Speed will light up.



Once done, put your modified plastic housing back on and move the LED's head so that the light is pointing upwards towards the "HI" & "LOW" bits on your plastic cover.



This one is a little tricky(i.e. Climate Control), because we have to leave the LED's pointing upwards and only once we've put the black plastic housing back on, can we move the LED's around.



Almost finished, this is what your completed PCB should look like.



You can now put the black A/C Panel casing back on, and maybe a few screws to help hold the PCB in place. I wouldn't bother putting anything else back on, because we're still going to be testing at this stage.



Here you can see how the LED Cluster for the Climate control looks like after putting the black A/C Panel housing back on.



First time I did this board, you can see that the Climate Control Lights didn't work for me. Due to a bad contact point on the positive resistor / LED leg and the PCB.



Put in the white plastic insert, readjust the contact points if it didn't work for you previously, and then push the LED's apart so they are facing 180 degrees from each other.



Should be working for you, notice how the plastic housing is important as it helps to disperse the LED's light all around the Climate Control area.



What it all looks like from a distance.



Another picture with the all the dials back on. If you have the Stainless Steel MKIV Dials, it will look like pure sex..!



This is the last difficult part of the A/C Panel. Once you have tested everything and are happy that it all works (remember to test the buttons to make sure all your indicators are working), you'll most probably be presented with the situation below. You put the black plate back on, and the resistors are sticking up too high for the cabling to go through. You will need to bend the resistors to the side, and I even wrapped a few layers of duct tape around the cabling to provide for some extra protection against the pointing tip of the resistor. Be very careful bending the resistors and you definitely need to test it once you've put the smaller PCB into it's slots.



Once it's all working, it's pretty much smooth sailing from here on. Put all the panels back on and reassemble the A/C Panel Cluster. Once you've reassembled everything, it should look something like this:



And thats all for this part...! Wasn't too hard now, was it...???

Ignition Ring

This a pretty easy mod to do. Remove the top part of the ignition ring to expose the bulb that needs to be replaced.



Showing Stock Bulb in stock bulb holder.



Swap over the stock bulb with the LED Bulb, you will probably need to shave off the sides of the bulb so that it can fit into the bulb holder socket.



Some more pictures of the ignition ring.






Ashtray Light

Another pretty easy one to change over.

On the Shifter Dash Panel, you'll find a wire + bulb holder running on the left hand side. I had a bit of difficulty getting mine out, I pulled and twisted a bit.



Once you have pulled it out, replace it with an LED Bulb, again, you will probably need to file the LED Bulb down from the sides so that the stock bulb holder doesn't bulge out!



This is what the finished modification should look like.




Rear License Plate Lights

Unfortunately I didn't take too many pictures while doing this mod, so you'll have to do with what I can provide. (I'll edit my post later on with some more pictures).

This is what the stock license plate lights look like. You need to remove a total of 4 screws to get to the bulbs.



Once the plastic lenses are off, you will need to twist the stock bulb holder to unlock it, and then remove it from it's location. Replace with the appropriate LED bulb (see first thread) and put it back in and twist lock it back in place. I think they are polarized, so if you don't get any light, spin the bulb around. While you've got the plastic lens off, you may as well give it a clean. If the rubber falls off, just use super glue to stick it back once you've finished cleaning / drying the lens.


Analog Clock (Late Model Only)

For those of you that have still kept the analog clock, or who just like (like me), this is a really nice mod to do. Again, I don't have any real pictures of this mod, I'll get some next time I have my dash apart.

The clock detaches from the dash by unscrewing two screws.

To remove the individual bulbs from the clock, simply twist and pull them out using a plier. This is what the stock bulb + holder combo will look like:



Remove the stock bulbs from the holder and put the appropriate LED bulbs (see first thread) in. You will need to shave the sides off the LED Bulbs to get them to fit nicely into the bulb holder without bulging too much. They are polarized, so if they don't work, spin the bulb around so the positive & negative side get reversed.

Here are some pictures of the different combinations.





Here are some pictures of the finished product...








And thats it....!!! All done! I will update later on with a few more pictures, and also a DIY for the front parking lights! Hope you were able to successfully do this, and get some satisfaction out of it..! Happy car modding...!

[Soup_TT]

Post reserved for any future additions which cannot fit in above posts due to size constraints.

[Aero-girl]

Your post couldn't have come at a better time.
Am going to try the same thing.
Can't wait...
By the way it looks sh*t hot!
I'm sure this will be very helpful
Cheers

[DrNick]

Great stuff.. you've put a lot of effort into this, thanks for documenting it with all the pics, makes it easier for me to decide which colour to go for

[supride]

WOW great write up.

billy plz come to syd. ill buy u plane tix and stuff just do mine hahah!

[BiGH]

More LED's soldered together to create a 4 LED Parallel Circuit.

I'd like to add one thing here - either be careful of the legs of the leds, or insulate the board (using electrical tape) becuase it can kill the leds. The legs of the LEDs should not be allowed to touch anything metal. I had this happen due to a misalligned led, and yep there went 4 leds

Also want to backup - only use quality leds on the A/C cluster.

Top writeup!

[SupraBoy]

awesome writeup.....

now.... how much to do mine?

serious.