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Thursday, 18 August 2016

Citroën C1 (Mk 1), Peugeot 107, Toyota Aygo (Mk 1) (2005-2014) - Changing the dash illumination colour.

Many many moons ago I wrote an article on changing the colour of the dash illumination on the very excellent C1,107 and Aygo cars. It's got lost in the mists of time somewhat, so I'm going to re-create it here, by popular demand! I did this some 6 years ago, so please excuse the rather bad photography (like it's ever been great anyway!!)

Best I add a disclaimer, in addition to the usual one on the right.

Don't try this at home. I will not be held responsible, under any circumstances, if you damage your car. This requires accurate soldering to delicate and tiny components. 

Right, having got that out of the way....

We'll start with the binnacle lighting first...

So, open the bonnet and disconnect the NEGATIVE pole of the battery. Done that? Good....

Close the bonnet and arm yourself with a No.1 and No.2 Philips screwdriver, and a 10mm spanner or socket, a good quality soldering iron, some solder, desoldering braid, decent tweezers, 10 off PLCC-2 type SMD LED's and 50 off 1206 SMD LEDs in the colour of your choice.... oh and a sewing needle (yes, really) and a bit of connector block.

Turn the steering wheel to the right, to reveal one of the binnacle cover screws. Remove it.....

Turn the wheel to the left, and remove the other screw...

After a bit of jiggling, remove the cover....

... to expose 2 10mm bolts....

... and remove the two bolts ...

... gently easy the instrument binnacle forward to allow better access to the wiring, and remove the connectors, starting at the top. Each connector has a little catch. Once the catch is pressed, the connector should come out of it's socket easily...

Don't worry about noting where all the connectors came from, as each one is unique and will only fit in one socket.

Now take the binnacle off, and retire to the workshop/kitchen/dining room table!

Cleanliness is the key here, so go and wash you hands, and if you have any of those nitrile or similar gloves, don a pair now. You don't want to be leaving fingerprints on the inside of your speedo once we've got it apart....

Now, gently push in the two clear plastic catches, as shown here....

And there are two similar catches at the rear of the speedo to unlatch too.

Once these are released, you can lift off the clear cover.

Next wrap a piece of wire or string round the pointer, and gently pull it off.

Now release the black plastic catches holding the surround in place, two shown here, and one on each side...

... and gently un-clip the surround....

.. remove the speedo face...

... and lift out the diffuser...

... remove the four philips screws holding the speedo electronics to the brown back & sockets.... one is a different length. Make note of which one it is!

Remove the speedo electronics from the brown back assembly. This will take some gentle prying to get the socket to release.

And place the back safely out of the way....

Now comes the tricky bit. First off, make yourself a DIY hole clearing tool, with a needle mounted in a piece of connector block..

Get yourself some good quality desoldering braid. Don't be tempted to use one of those nasty spring-loaded pump type desoldering tools. They have an unpleasant habit of removing the solder, along with the tracks on the board, which will be difficult and time consuming to repair. I personally rate Chemtronics braid. It's good stuff....

Now, desolder the 21 pins connecting the odometer and fuel gauge LCD to the board. Take your time. Breaking this would not be good news. Once they are all desoldered, check each pin can wiggle a bit in the hole with the needle, and lift off the while plastic front, along with the LCD. Clean up the holes, by warming the DIY hole clearing tool with the iron, and inserting it into the holes, pushing out any remaining solder. Clean up with the braid, and breathe a sigh of relief.

Now we come to change the LED's themselves.

PLCC-2 LEDs have a small cut out in one corner. This marks the cathode. There is a small arrow printed next to each LED and the cut-out must be at the pointed end of the arrow, as shown in the picture...

Using the desoldering braid, desolder the LEDs ringed in the picture. LEDs ringed in red are the backlight LEDS, and the LED ringed in blue is the illumination for the pointer. You can make them different colours if you wish...

Heating the LEDs for too long with the soldering iron will destroy them, which isn't much of an issue when removing the old orange ones, but you want to be careful when soldering the new ones in place.

Once this is done, carefully reunite the LCD display, still on the white surround with the electronics are resolder it in place. Replace the electronics back into the rear cover, making sure the socket seats home, and replace the 4 philips screws, ensuring the long one goes back in the right hole. Replace the diffuser, and fit the face. When pushing the pointer back on, fit it pointing towards 110 MPH, and once seated move it round to 0.
Replace the black cover and the clear cover. Done.

Ignore this bit if you haven't got a tachometer (rev counter).....

Squeeze the tacho slightly, and grip the front surround. It should pop off easily.

Remove the philips screw in the rear of the tacho, allowing it to be pulled out slightly.

Unclip the black plastic surround and remove the surround and plastic lens in one piece...

Remove the pointer with a piece of wire or string in the same manner as we removed the speedo pointer.

Undo the two screws securing the face to the speedo...

Remove the electronics and face in one piece, disconnect the plug, and remove the two screws.

Replace the two LEDs shown, remembering the arrows...

and reassemble.

Take the binnacle back out to the car and re-fit it.

Good eh??

But we're not done yet!

Radio looks awful in orange now doesn't it? ... and that heater illumination ... ugh! ... and the headlight aim switch ... horrendous!

Let's deal with the radio and heater.

Set the heater fan to the II position, and locate the small gap in the knob underneath. Gently prise it off, using a piece of cardboard to cushion the dash so we don't scratch it.

Remove the screw.

Get a credit card or something (I've got strong finger nails!) behind the cowling, and pull it off. It shouldn't put up much of a fight.

4) Remove the pulgs and sockets from the radio (one white, on black (have little release levers on one side) and the aerial plug (just pulls off)) , and the heated rear window switch, hazard warning switch and (if you're lucky) the air con switch (have release buttons on the top or bottom).

These are green white and black respectively. Cart the whole assembly inside to the operating theatre.

Remove the radio from the dash. Two sprags holding the radio in each side. Two on the top and two on the bottom.

This requires use of 14 fingers, or some choice expletives, or both.

Put the cowel to one side, and remove the front from the radio. Two small philips screws each side, and one clip each side, two on the top and bottom.

12 fingers only required this time, also fewer expletives.

Remove 8 screws from the display PCB and remove. It will unplug from the push button sub-panel, leaving that in place.

Remove 4 screws from sub panel and remove.

Right. Here are the LEDs we're going to change. They are 1206 SMD LEDs, you'll need 50 of them (you'll have a few left over)

1206 LEDs are tiny!

There are 17 on the sub panel and 27 on the display PCB. I know I told you to get 50 , but you will lose some ;) And anyway , it's a minimum order quantity :D

Remove a new diode from it's packaging to examine it. Marked on it somewhere is it's polarity. The mark will indicate the cathode. In the case of my diodes, there was a green mark on the underside. This pointed to the cathode.

The cathode of the diode on the PCB is marked with a continuous line around the end of the diode. In the case of the picture below, it's to the right. All of the diodes we are changing have there cathode to the right, or to the top if they are vertically orientated.

Desolder the first diode (I actually desoldered the whole lot, it saves time, but if you're new to this, take your time). Use the solder wick to suck off the solder, then you should find a slight push with the iron tip, will remove the diode from it's lands. Use a nice fat tip for this job. Clean up with solder wick. Add a touch of fresh solder onto each land. The PCB's in this radio are really well made and will tolerate quite some abuse before the print becomes damaged.

Grab your new diode in some tweezers, making sure you know which end is the cathode. Line the new diode up to it's solder lands, and just melt the solder with the small iron, so as to solder the one end of the diode in place. Remove the tweezers and melt the solder on the other end.

Repeat for the other 16 diodes on this board.

Put the board to one side , it's time to tackle the display board .... "What's so tricky And?" I hear you say .. it looks similar to the other PCB .. unfortunately there are 12 diodes UNDER the LCD crystal display, so it's got to come out.

Twist the 4 tags holding the display screening can to the board, and desolder the two points.

Desolder the two multipin connectors to the display, just underneath the CD slot. TAKE YOUR TIME. The display crystal is very fragile. One crack, and it's game over. I chose to flood the connectors with solder and run the iron up and down the whole length until every joint was wet, the display will then gently come out. Solder wick is another option. Once the display is out , put it somewhere safe.

Using the hole clearing tool (OK , it's a pin and a bit of connector block) and the solder braid, clean up the connectors.

Change the diodes in the same manner as you did on the first board.

CAREFULLY re-fit the display. Don't forget to twist the tags and solder the can.

If you have a bench supply, plug the boards in and power up to check it all lights up nicely. You'll need to connect +12 Permanent, and +12 lights.

Damn, that looks good....

Right. That AUX socket on the front... what a pain. Lead from your phone dangling all over the place looking untidy... Fancy moving it somewhere sensible? Read on.....

Move back to the sub-board, and looking at the aux connector, cut the track as shown...

It's uncut here...

...and after the incision is made. This is to fool the electronics into thinking there is a plug in the socket.

Turn the PCB over, and connect a piece of twin and screen cable to the points as shown.

Right channel is red, left black and the screen is ground.

Replace the sub-panel, and the main display PCB, and carefully route your new cable out of the front... it's tight , but mine fitted.

Refit the radio in the dash, again routing the new cable. I chose to route mine to the rear of the clutter box...  You'll need to solder a 3.5mm stereo jack to the end, tip is left, ring is right, and sleeve is ground.

OK... it's going well... now the heater... You can buy replacement LED lamps for the bulbs in there now. I chose to use a couple of ordinary 5mm blue LEDs, and solder them in.. It's easier if you get the right LED bulbs.

I cut the tops of the LEDs in an attempt to diffuse the light a bit, otherwise you'll end up with two spots. Not a good look. Note the 780 ohm resistors.

Undo the panel mounting screws...

 ...both of them...

...and hinge the panel forward. You will see the old bulbs in there holders, just pull 'em out, and fit the new ones or solder in your LEDs. If they don't light, you may have them in the wrong way round. If the light is still focussing as two spots, just bend the LEDs so they face away from the front. This is easier if you have soldered separate LEDs, as I did. Once it's nice and even, screw the panel back in place, and refit the radio... Give it a try.... Nice....

... except for the headlamp aim switch ... still orange... nope, it'll have to go....

Remove the philips screw holding the outer dash on....

Pull the dash down, and pop the switch out, un-plug it and back to the operating theatre....

Pull off the cover.....

Cut off the orange LED.

... and solder in a PLCC-2 diode in it's place, with the cut-off corner facing the outside edge.

Push the cover back on, and refit the switch and dash.....

There. It's done. In all it's blueness....

... or pink if you prefer ;)

Thanks to Hanna for the pink pic. White looks good too!


  1. Ye gods MR a of the D. Just how brave can you get?
    This magnificent project is so full of caveats and pitfalls that I'd rather attempt to gnaw one of my legs off than attempt this micro surgery. I always said that you were wasted, but really! Eyesight is so important here, so is a steady hand and patience, sadly I lack all!!! another classic, but sadly this one Andy I'll avoid.
    Thank you for the most entertaining missive Sir!

  2. Hii! do you have some order information of the LEDS? PLCC2 LEDS and the 1206 LEDS?

    1. You'll find them commonly available from all good component places, and eBay. Vf isn't that important, current limiting is installed on the boards. I've not found any that don't work...

  3. Very pleased to find the pinout for the aux socket as mine has been banjaxed by a careless former owner and I can't find a replacement. I'm going to have to solder a cable onto the PCB but what I'm not clear on is why you need to cut that track? Also will the CD player still work? Many thanks, best wishes Andrew

    1. The track is cut so the unit "sees" the input all the time, so you are able to select AUX with no physical jack present. Without the cut, the contact remains shorted to earth, and the unit fails to recognise the aux input. Hope this helps.

  4. Super-helpful, many thanks. Beats me why they need switching in the socket as well as presumably an electronic source switch activated by the button but there we are, as I can't seem to source a replacement socket anywhere a cable looks like the answer. Great blog!

    1. I suppose it's a little unnecessary.... I blame the person who wrote the firmware... you know what software people are like ;)

  5. ;) I realised in the night that as I've remived the old broken socket from the pcb I won't have to cut the track as those switch connections are now open circuit anyway. Thanks again for this great post which encouraged me to take the stereo apart.

  6. Thanks for this I just want to change my left indicator led as it's stopped working, possibly it's only a dry solder joint.

  7. why do you need to desolder the 21 pins connecting the odometer and fuel gauge LCD to the board?

  8. Is it possible to get white scale on rev meter and leave orange/red pointer?

    1. Hi Adam, It's actually very difficult to change the pointer colour.