Audi Coupe OEM+ Interior Lighting Guide

[Flat on my back]

Wow...

Is there any way of powering the DL switch on the bench to check the bulb operation before it goes back into the console?

Works on the bench, not in the car...loom fault...type of thingy.

[macspring]

Jase,

Just what I needed to know, thanks very much.

Kind regards.

[Jas11n]

You can use one of two types of bulb for this. As you can see in mine, I used small wired bulbs from Maplins, code >>> PG77J
If you want the image to be slightly dimmer, the small bulbs used earlier in this thread for the mirror control switch are just as good.

Now, normally the text "DIFF" is illuminated at all times the car's ignition is on (the drivetrain image will only light with ignition AND lights).
If your text isn't illuminated, the red LED inside the push button will have gone. There's also a bulb inside that illuminates a yellow triangle behind the text. That will only illuminate when the difflock is on.

To remove the push button unit from the main body, get your blade and insert it down the side, gently lever the blade against it while pushing from the other side and it will come out from above;



Once it's out of the main body, again use your blade/tool to carefully lever up the main body from the tangs on the internal part, there's two either side;




The LED's used for the window switch illumination are again perfect for the replacing the LED in the push switch should you need to (CJ70M). You need to know which is the earth side of the LED (short leg of the LED), I've arrowed it below. If you are replacing this, then you'll need to junk the resistor in there, use a piece of thin wire to follow the old resistors route around the switch, or route the longer leg of the LED round the back



Here's what it should look like;



And when the difflock is on;



I'm sorry I've not shown any soldering of new bulbs, but as I said back at the beginning, my switch "was" ok as I'd done it way back when I bought the car years ago.
Big thanks to Sal for the replacement switch

[If someone has a spare earlier switch, or maybe a switch with duff illumination that they want fixing, let me know and I'll do a run-through for that too]

[Jas11n]

Right, finally got a bit of time to write this up. This is for the smaller buttoned switch.

Ever heard of the saying "If it ain't broke, don't fix it?"
I need to have that in mind next time. This exercise the other day cost me a diiflock circuit board. The things I do in the name of Audiness There was nothing wrong with my switch illumination, but after I finished there was.

First up, look at this picture below, look at it a good few times, even open it in another window, whatever. Just take note.

You are looking at the way the plastic block is screwed to the main body of the difflock unit.
When coming to reassemble your switch after you've replaced which ever blown bulbs, you CAN fit it 180° the other way. If you do this, and reconnect it to your wiring plug in the car, IT WILL blow the small black three legged transistor (I assume it's a transistor) and the circuit will be junk.

The block must be refitted exactly as shown below



Looked at the above picture??? Look again.

Right; First up, as said, I haven't got a run-through of the earlier large buttoned switch, I haven't got one to do a run-through on it.
Though the earlier versions drivetrain image is the same size, the push switch is a lot larger and is the same size as the switches on the dash.
If you want a later one, you'll need the rear centre console too, the oblong hole it fits in is a lot larger on the earlier consoles. The multiplugs on the rear of the earlier switch are different too.

There's two ways to remove it, it's up to you which way you do it. If you pick my way and damage it, don't blame me. Remove the rear centre console if you must.

I use a blade and carefully slot it under the front, then prise the front up;




Then do the same at the rear




Pull off the two multiplugs then remove from the car;



Remove the two screws and put the block to one side;



Now you can just lift up the circuit board;



Flip it over to reveal the bulbs. The yellow arrows point to the two bulbs that illuminate the drivetrain image, the green arrow points to the bulb that illuminates the green spot seen in the rear axle of the image when the difflock is on.

[Jas11n]

Cheers chaps.
A big part is having the right gear, I know it may sound daft, but then you wouldn't go and try and change your turbo with a set of plastic mechano spanners and a torque wrench made from chocolate.
A good iron, 30watt is enough with a good fine pointed tip. No use trying to solder with an iron that gets as hot as a nuclear reactor and has a tip the size of a blunt cold chisel.
A de-solder pump is useful, a selection of small jewellers screwdrivers, a blade (swiss army knife for me) and a jewellers third hand is another tool that helps.

As John says, watch for the parts that want to have your eye out, the stalks on the steering column are büggers for that

I was going to have a bash at the door marker lights today on the S2, untill I got up.
A temp of -3 and snow showers........erm! I think not .

[newsh]

Great stuff Jase, I've had a go at some of these in the past and they're a fiddle, its always the first one thats really tricky, when you find out about that spring that sends the small part into the far corner of the kitchen.. Good work, you're pointing out the pitfalls, I'm inspired to sort out some of my switches now. I particularly like the idea of illuminated door handles too.

[Fat Audi 80]

Wow now thats a good offer

Yes, you could regret that Jase!

Another storming write up, you make it look easy, but that is top quality. Great macro shots too!

[A80Avant]

Hmm...ill give you a call if there is time...

[Jas11n]

jase i admire your electrical skills,you know that by now,so next job will be to fix the rear door window trigger light..only i would have to come to you as you have to take the doorcard out to reach the switch,which is different than the ordinary ones as it doesnt have a plug,it is completelly soldered with the cables...

No problems Vasilis, you are always welcome. I'm around all weekend if you aren't up to much

Wow now thats a good offer

Includes the difflock switch too

[YELL MAN]

Just realised this, inner door handle removal explanation above is for a Coupe, I'm not yet past it enough to own an avant (joke)

If anyone doesn't think they are patient enough to replace any of these, get in touch. I'll replace them for you, all I ask is you pay for postage both ways

Wow now thats a good offer

[A80Avant]

jase i admire your electrical skills,you know that by now,so next job will be to fix the rear door window trigger light..only i would have to come to you as you have to take the doorcard out to reach the switch,which is different than the ordinary ones as it doesnt have a plug,it is completelly soldered with the cables...

[Acidburn]

think the avants handles are not much different from what i've seen of my avant.

[Jas11n]

Just realised this, inner door handle removal explanation above is for a Coupe, I'm not yet past it enough to own an avant (joke)

If anyone doesn't think they are patient enough to replace any of these, get in touch. I'll replace them for you, all I ask is you pay for postage both ways

[Jas11n]

Here's the points on the PCB which you need to de-solder and withdraw the old bulbs from the other side. Old bulbs removed.




Again, I choose this time to reuse filament bulbs, I'm not sure if the 3mm LED's would be bright enough, even though they are SB versions.
The bulbs are again from Maplins, code >>> BT43W.
They are a small wire terminal bulb, 12v 60mA and are perfect size for size replacement. I've used these in difflock, ATD and heated seat switch replacements.



New bulbs soldered on.



Then use a 12v power source to check you've made good solder joints,



Reassembly is just a reverse of removal, REMEMBER not to turn the black casing upside down, you may lose those ball bearings.
One last check to make sure reassembly didn't undo your hard work.



Then go back to the car and refit it.

Should now look like this. "Note" Dunno why, but I thought the two direction buttons were illuminated, but apparently not. The white "L" and "R" symbols are just painted on. Funny how you have a preconception about things





Jase..

[Jas11n]

Make sure to leave the black switch body facing down (control buttons down) Once the innards come out you'll see why. There's two ball bearings which you don't want to lose. Put the black body to one side, it's not needed until you come to reassemble.



This what you are left with;




You need to lift up and remove the rubber cover which will expose the bulbs fully.



Now you need to separate the circuit board away from the white plastic casing, just push the legs of the terminals out and they come apart.