www.InternetWork.org.uk - Home Of The Blue Dash Conversion

How To Change The Dash/Heater Back Lighting - Updated 17/01/11

Background Details

As you're probably all aware, the Supra as a lovely green back lit dash. Although still a modern looking car, but with out-dated dash lighting, especially when compared to the likes of the modern VW's!. This guide (I say guide as i don't want to be responsibly if it goes wrong) shows you how to change the colour. I used blue LED's, but there's nothing stopping you from using any other colour LED's. I have carried out a red/blue combination, blue/white combination, white etc...

And now...

After a lot of people of asking me "how do you do it?" I have decided to start making the dash conversion (heater control panel/ODO/Clock/dash back lights/Ignition & Cigar Ring lights/Window switch/Trac & Auto Spoiler switches) on an exchange basis - I send you out a converted heater control panel, ODO, Clock, Cigar Bulb Holder, Window switch, Trac & Auto Spoiler switches and direct T5/T10 LED replacement LED Bulbs for Dash Cluster and Ignition Barrel - on receipt, you send me your heater control panel, Cigar Bulb Holder, Window switch, Trac & Auto Spoiler switches. If you're interested in this option, please click here

First things first. Please read the guide BEFORE you start


Parts Required - all parts are available from www.maplin.co.uk OR www.ebay.co.uk, but if you buy from Ebay, expect everything in vast quantities! LED's are also available from www.component-shop.co.uk

Tools Required

  • 15W fine soldering Iron & Solder
  • De-soldering tool
  • Wire Cutters
  • Knife (Stanley)
  • Dremmel with thin cutting disk (to cut the prototyping board)
  • Glue Stick (pritt-stick)
  • Junior Hacksaw/Dremmel
  • 12mm socket (to remove locking nuts on Air Con Unit)
  • 10mm socket (to remove battery clamp)
  • Philips Screwdriver
  • Flat Bladed Screwdriver
  • Thin Nose Pillars (optional)

Parts Required - If you click on the headings, it will take you straight to that section

Heating Controls (UK & JDM Spec)

  • 21 x 3mm Blue LED's
  • 11 x Rectangular LED's (2 x 5mm)
  • 1 x 4v7 Zener Diode (Some control units have this value diode fitted from factory)
  • 1 x 5v6 Zener Diode (Optional)
  • 8 x 6.2k (6200 Ohms) Resistors
  • 2 x 390R Resistors
  • 3 x 510R Resistors
  • 2 x 5cm Lengths Of Wire
  • 2 x Strips Of Prototyping Board

Dash (Tacho/Speedo) (UK & JDM Spec)

  • 6 x 5mm Blue LED's
  • 6 x 390R Resistors
  • OR 3 x T10 LED Bulb, and 1 x T5 LED Bulb from ebay - The T10's need to Superflux LED's as there very bright and wide angle

Ignition Barrel (UK & JDM Spec)

  • 1 x 5mm Blue LED
  • 1 x 390R Resistor
  • OR 1 x T5 LED Bulb From Ebay

Digital Clock & ODO (UK & JDM Spec)**

  • Blue Gel Sheet (From Ebay)
  • Clear Plastic (CD case is ideal)

Driver Window Switch (UK & JDM Spec)

  • 1 x 3mm Blue LED

Trac/Slip Control Switch (UK & JDM Spec)

  • 1 x 3mm Blue LED
  • 1 x 1K Resistor

Auto Spoiler Switch (UK & JDM Spec)

  • 4 x 3mm Blue LED's
  • 3 x 1K Resistors

Heated Seats Switch (UK & JDM Spec)

  • 4 x 3mm Blue LED's
  • 2 x 1K Resistors

Head Light Washer Switch (UK Spec Only)

  • 1 x 3mm Blue LED
  • 1 x 1K Resistor

Rear Fog Light Switch (UK Spec Only)

  • 1 x 3mm Blue LED
  • 1 x 1KResistor

Dim/Dip Light Switch (UK Spec Only)

  • 1 x 3mm Blue LED
  • 1 x 1K Resistor

Cigar Lighter (UK & JDM Spec)

  • 1 x 3mm Blue LED
  • 1 x 1K Resistor

If your interested in trying the door lock ring light LED conversion, click here.

**You do not need the gel sheet if your Supra is the facelift version ( 1996 on) As the clock and ODO are both analogue**

You don't have to change the Orange LED's (DE-MIST and REAR SCREEN), but its advisable. The reasoning behind this is that different coloured LED's require different amounts of current to operate (LED's are current dependent, not voltage), so the orange LED will be brighter the the blue LED's. Its possible to try and balance them by using different value resistors, but to be honest is just easier to change them to blue!

There are some optional parts, The 5V6 zener will cause the LED's to be slightly brighter when the lights are switched on.  This is a matter of choice, I prefer a slightly dimmer light and actually used a 4v7. The standard diode seems to vary from 3v9 to 4v7 some find this fine. The larger the diode, the brighter the LED's will be at night - some may find that it glares when the cabin is dark.

 Remember! ALWAYS disconnect the battery if you are going to carry out any electrical work!

Heating Controls 

Step 1

  • Remove all the dash trim. If you don't know how to, look Here
  • Remove the heater controls from the trim, the Control unit is fixed to the center console with 3 screws

Step 2

  • With the control unit removed, remove all the visible screws, including the one which passes through the PCB.
  • There is a clip either side of the back which help hold the PCB. Release these clips otherwise you will not be able to remove the back section.
  • Slide off the back when the clips are opened. 
  • With the back off, disconnect the lead that goes to the temperature control.  The connect PCB can now be bent over gently to show the remaining screws.  Take these out.
  • Remove the fan knob, careful to catch the collat.  Undo the center nut.

    The main PCB will now come free from the case.



Step 3

  • Remove the plastic LED holder (Two have been removed in the picture)
  • De-solder 1 by 1 the LED's  Do not use too much heat or force otherwise the PCB tracks will start to lift.
  • Replace the LED's with a blue 2 x 5mm LED at the same height.  Insure that they are put in the right way around otherwise they will not work.  The PCB is marked with a + sign, get the LED and look at the bottom edge, there is a flat on one side.  This side goes towards the -.  I.E.  The flat MUST NOT go into the marking +.  If you get it wrong it wont damage anything, it just means you will have to do it again!


Step 4

  • Watch the heat from the soldering iron, LED's can be damaged by too much.  
  • You will need to cut part of the plastic holder off using either a junior hacksaw or a dremmel - just leaving you the thin section around the LED them selves.
  • The picture shows all the blue LED's in place and the plastic holders put back on (but not cut)



Step 5

  • The zener diode now needs to be change to allow the LED's to dim when headlight are put on.
  • ZD1 is on the connector PCB.  Remove the diode.  Make note which way round the diode is, there is a white or black stripe on it, when replace with the new zener diode this MUST be the same way round.  This is very important.  If you get this wrong you will do some damage.

I recommend using a 4v7 diode (personal preference) as some unit seem to have this fitted.

Step 6

  • Now if you are fussy like me and have ordered the resistors as well change these over.  Look at the main PCB and you will see letters R with a number after them.  Change the following resistors to 6k2 ohms :

  • R1, R2, R3, R4, R5, R6, R7, R8

Step 7


Step 8

  • Take the prototyping board, and cut into strips - as shown in the picture.
  • You will need to make sure that they are narrow enough to fit in between the white plastic parts and the silver buttons.
  • The Yellow marks denote the position of the LED's

Step 9

  • Solder the LED's to the strips
  • Solder a 5cm of wire to the positive strip
  • Solder the resistor to the negative strip
  • Repeat the step for both LED strips

This picture shows the LED strip for the top row, as the wire is in the middle of the strip. The LED strip for the bottom row has the wire/resistor offset to the right, between LED's 4 and 5 (counting left to right) - It also shows cut 5mm LED used instead of the 3mm LED's (old picture)

Step 10

  • Place the LED strips on to the main PCB, feeding the wire/resistors through the holes
  • Solder the wire/resistor as shown.

Step 11

  • Take 2 x 3mm LED's and solder on a 510 Ohm Resistor to each negative leg, and feed through the hole as shown in the top picture. Making sure the negative is facing towards the top
  • Solder to the PCB as shown in the second picture

Step 12

  • Take 1 x 3mm LED's and solder on the 510 Ohm Resistor to the negative leg, and feed through the hole as shown in the top picture. Making sure the negative is facing towards the bottom
  • Solder to the PCB as shown in the second picture
  • Solder the second LED directly to the first LED as Shown in the first picture



  • Take the white plastic part and open out the hole as shown. And refit.

Step 13

  • At this point it's advisable to test the PCB/LED's to ensure that everything is working. It should light up as shown

Step 14

  • Remove the Temp Dial from the front panel using the clips as shown
  • Before placing the front of the heater control unit onto the PCB, make sure the 2 LED's on the top left of the PCB are pointing straight out together


Step 15

  • Place the front cover onto the PCB, and separate the LED's as shown.
  • Refit the Temp Dial.
  • Refit the Knob


Step 16

Now you can put the unit back together.  Before you fully screw things together it may be worth checking that all the LED's have been soldered in correctly.  But be careful that no parts of the unit come into contact with metal on the car.

Switch on the headlights and check that they dim correctly, if you think that they are to dim then change the zener to the 5V6 one.  If it doesn't dim at all then it is possible that you have the diode the wrong way round, or it is not soldered in correctly.

Everything working - great, disconnect and screw it all back up.  If its not working (then you are probably wishing you never stated this), disconnect everything.  First check your soldering and then check it again!! Look for any solder bridges that may have formed.  Then check that you have the LED's the correct way round.  Hopefully it will be one of those two.

There is an additional mod which can be made to the unit, its now know as the "blue knob" mod.

If your interested on carrying out this mod, click here.

If you have problems or you want to do something different with the LED's drop me a line, and I will see what I can do.

A word of warning, it is not recommended to switch on the ignition with the controller unit unplugged.  The AC management unit records it as a fault.

Dash (Speedo/Tacho) Clocks
If your going to use the T5/T10 bulbs, skip this section as there direct replacement.

Step 1

  • With the clocks already taken out, remove the 4 bulbs (3 large and 1 smaller)
  • Where the bulbs were, mark which are positive and negative - by tracing the tracks
  • Put some solder onto the contacts - but be careful not to melt anything!



Step 2

  • Take 2 LED's and 2 resistors.
  • Solder 1 resistor to the NEGATIVE led of the LED.
  • Solder the positive legs of the LED's together, and solder the resistors together. Do this TWICE.
  • Take 1 LED and 1 resistor
  • Solder a resistor to the NEGATIVE led of the LED. Do this TWICE.

You will end up with 4 sets of LED's The paired LED's are for the middle two slots, with the singles for the remaining slots.

There's an alternate version of this using the existing bulb holders. Click here

Step 3

  • Solder the positive leg of the LED to the positive pad, and the same again for the negative leg. Point the LED's to that they are in contact with the transparent plastic inside the clocks.


Ignition Barrel


If your going to use the T5 bulb, skip this section as there direct replacement.

Step 1

  • Remove the small clip on the back light ring
  • Remove the Bulb

Step 2

  • Cut the ground wire (white/black) and cut a 1" section out. Solder in resistor to the wire.
  • Insert the LED/resistor in to the bulb holder - checking for polarity - if it doesn't work swap them over.
  • Reassemble.

Digital clock and odo

Step 1

This involves cutting the plastic to fit, so be careful with the knife!

  • Remove the clock from the trim
  • Remove the front cover - be carefully as 3 plungers will probably fall out!
  • Remove the brown! plastic filter (you might break the retainers, but this does not matter)
  • Cut a piece of plastic slightly larger then the hole.
  • Attach a piece of the gel sheet to the plastic, and glue the plastic in.
  • Reassemble



Step 2

  • Remove the ODO from the trim.
  • Remove the brown filter.
  • Cut a piece of plastic to fit the hole.
  • Attach a piece of the gel sheet to the plastic.
  • The plastic does not require any gluing as when its fitted back to the trim, it is sandwiched between the trim and the ODO unit
  • Reassemble


Drivers Window Switch 


The window switch is removed as per the instructions found here.

Step 1

  • Remove the 3 rockers by using a thin bladed screwdriver between the pivot and the rocker its self.
  • The "window lock" button just pulls off

Step 2

  • From the back of the unit, remove the 5 screws as marked on the picture.


Step 3

  • With the front and rear covers removed, remove the screw as marked on the picture.

Step 4

  • On the back of the unit, remove the plug case so the LED solder pads are exposed.


Step 5

  • Desolder the pads as marked, remembering which is the negative leg - an easy way to remember, is the its the one connected the resistor.

Step 6

  • New LED fitted, showing negative leg.


Step 7

  • Reassembly is the opposite of disassembly.
  • Refit the plug case, and screw
  • Refit the top section of the switch body
  • Refit the bottom section and the 5 screws
  • Refit the 4 buttons
Traction/Slip Control Switch

Step 1

  • Using a flat bladed screwdriver prise the button off.
Step 2
  • Prise the 4 clips open - 2 on the top, 1 either side. Be quite careful as it is possible to break the case.
  • Pull the front section off

Step 3

  • Remove the brown rubber square
  • Using a thin flat bladed screwdriver insert it into the area shown and pull the switch from the body and remove the small PCB. When you pull the PCB out you may find that a small spring and a metal contact will fall out. Do not loose these!

Step 4

  • Remove the existing bulb
  • Solder a 3mm LED and resistor onto the contact pads as shown.

Step 5

  • When reassembling, you need to put the PCB in to the switch (with the metal contact and spring) before it is slid back into the switch body
  • Refit the brown rubber square
  • Refit the front section
  • Refit the button
Auto Spolier Switch

Step 1

  • Using a flat bladed screwdriver prise the button off.
Step 2
  • Prise the 4 clips open - 2 on the front section, 2 on the rear section. Be quite careful as it is possible to break the case.
  • Pull the sections off
  • On the main body, at the back there are 2 coil springs, a white plastic bar and a small spring - Note the orientation of the white bar and the small spring for re-assembly.
  • Remove the Brown rubber square from underneath
Step 3
  • Prise the 2 clips as shown in the red circles.
  • Remove the section from the body of the case.
  • Remove the existing bulbs
Step 4
  • On the bottom side of the PCB, Desolder the two joints as shown in the picture.
  • Once the solder is fluid, you may need to use a pair of thin nose pliers to close up the contacts from the metal strips mounted above the PCB.
  • The contacts may break, but it is nothing to worry about.
Step 5
  • Solder on the 2 LED/Resistors as shown taking care to note the orientation of positive/negative.
  • The led at the front is a straight swap for the original, again take care to note the orientation of positive/negative.
Step 6
  • Solder on the LED/Resistor to the top section as shown taking care to note the orientation of positive/negative.
  • You may need to rough the surface of the metal strips to allow the solder to take hold.

Step 7

  • Assembly is the reverse of disassembly
  • When placing the PCB back into the top section, remember to solder the 2 contacts back up, or the LED will not light up
  • Place the top section/PCB in to the main body.
  • Refit the 2 coil springs, white plastic bar and small spring
  • Refit the front and rear sections
  • Refit the 2 buttons
Heated Seat Switch
The process for this switch is the same as the Auto spoiler switch except that their are 2 LED soldered to the front of the main PCB
Headlight Washer Switch

Step 1

  • Prise the clips as shown
  • Remove the switch body from the button
  • Remove the white clip

Step 2

  • Remove the spring
  • Release the 2 clips as shown
  • Remove the inner section from the button

Step 3

  • Remove the tab as shown, to allow the LED to be fitted

Step 4

  • Solder the LED/Resistor as shown
Reassembly is the reverse process
  • Refit the inner section.
  • Refit the spring and the white clip.
  • Refit the button to the switch body
Rear Fog Light Switch
The process for this switch is the same as the headlight washer switch, the orientation of the LED is also the same. The only minor difference is in white clip.
Dim/Dip Light Switch

Step 1

  • For such a small switch, it has allot of clips!
  • Remove the front section by releasing the clip as shown
  • Remove the existing bulb

Step 2

  • Remove the rear section as shown, the 2 clips for this are self explanatory

Step 3

  • Remove the top cover as shown, the 4 clips for this are self explanatory

Step 4

  • Lift of the top of the knob, as shown.

Step 5

  • The orientation for positive/negative is shown here, you may need to rough up the contacts to allow the solder to take hold, you will also notice that their is not much room to work on!

Step 6

  • Solder on the LED/Resistor as shown
  • You may need to adjust the position of the LED so that if fits inside the knob without impeding the function.
  • As an alternative, you can file the front of the LED so that it is flat.
Assembly is the reverse of disassembly
  • Refit the top of the knob
  • Refit the top cover
  • Refit the rear section
  • Refit the front section
Cigar Lighter

Step 1

  • Remove the bulb AND the 2 metal contacts as they are attached to each other.
  • Cut as shown in the picture


Step 2

  • Reinsert the 2 metal contacts
  • Take the 3mm LED and bend the legs so that there the same distance apart as the contacts on the bulb holder.
  • Solder the LED on so the the LED in pointing down

Step 3

  • In the car, locate the loom for the cigar lighter and cut a 1cm section out of the negative wire (white with black stripe)
  • Solder the resistor on, and cover in insulation tape.

This is the same method as the ignition barrel light.

Reconnect the bulb holder to the loom, making sure you connect the negative side of the LED to the negative wire, or it will not work!

There is an alternative method to the one described which is a bit more trickier but it does not involve cutting the loom. If you interested in this method, click here.

Now that all the bits have been done, reassemble the whole lot - and wait for night time! Hopefully you should end up with something similar to this.

If you have any problems, please to not hesitate to Email Me! and I will try to resolve the problem!

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