Rev counter light

[Dr H]

I've got a really weird dark spot on my rev counter. Between 1500 and 3000 rpm there is hardly any light at all.

I'm presuming there is more than one bulb behind the rev counter and that I have to remove the cluster to replace it. Can anyone tell me where to get a bulb and wether I have to solder it or push it in

Also what is required to replace the temp display light (as that went ages ago) is it a white LED or small bulb.

Cheers

[Alistair C]

tach bulbs are easy to change and just lock in place with a 1/4 turn.....they also have a little red coloured boot on top for the red glow....

...available from VAG (halfords ones don't fit
info for removing the cluster is all on the holy central site.....

Ambient temp bulbs.... afaik its a sealed unit..... so good luck!

[S2 Ant]

I'm sure i remember reading either here or on S2 Central that to do the ambient temp bulb you have to remove the old and solder a new one on.... i could be wrong tho....

This bulb has gone on mine so am interested to know 100% how its done.

[Pete_RS2]

Ambient Temp Gauge

The ambient temp gauge certainly is a solder job. I did mine about a year ago.

The instructions are on S2 Central. Look under Technical, then Instruments & Cluster, then Related.

[Sidspud]

I changed the bulb on mine at new year. I got one from a duff fog light switch. The bulb was a little bigger than it should have been and is also a little bit brighter than it should be, but it works.
You just take the stalk cover off (2 screws), take the dash out (2 screws), remove the temp display(2 screws) and finally remove the back cover of the unit (another 2 screws). Unsolder the duff bulb and solder in a new one.
The only thing I would suggest is that you look out for is the 2 little rubber bits that slide down the side of the white plastic diffuser. These are very easy to lose, but they are essential as they transfer the signal from the board to the LCD. Without them, you'll have no display at all - £60 from VAG Parts.

If you have all the bits to hand, you can probably do the complete job (including reassembly) in about 10 minutes.

[andre]

Temp display bulb

Hi there

I did my temp display back light a while ago and it was pretty simple. It goes like this:

You have to remove the gauge pod. Then remove the temp display unit. Once you take this unit apart you will see the tiny (dead) bulb on the equally small PC board that comes out of the unit casing. You will need to unsolder the dead bulb and replace it with a new one. You can get the bulbs from most decent electronics places. Simply solder in the new one and re-assemble.

I decided to rather follow the LED route as I did not want to have to replace the bulb again.

A few notes for those who are intersted:

I decided to use LED's instead of the mini-bulb since the LED should
last longer. The submin red 12v LED works very well, only things to
be aware of are:

1) The holes in the PC board are too small for the legs of the LED.
You will have to drill them out with a very small PC board drill (<
1mm, not sure of the exact size). However, the holes are "tubed" so
there is a copper tube in the hole that connects the top of the PCB
to the bottom layer, this tube will get drilled out. Not a major
problem, but when you refit the LED you will have to solder both the
top of the PCB as well as the bottom. In fact you only need to solder
one of the legs on the top since the other has no copper around it.

As far as determining the polarity of the LED, it's quite easy. You
just follow the PC board track from the main +12v feed off the plug
and it leads to one of the pins of the light. That is then the
positive side of the LED (long leg)

Tip 1: Make sure the LED is as close to the PCB as you can get it since it has a bit of a "spotlight" effect which is made worse if the LED sits closer to the LCD screen above it. I did not check this and have a slightly brighter spot on the display. Not to serious, but can bug you if you are a perfectionist.

Tip 2 (if you have airbag): You will most likely want to test the light before you put everything back. It would seem as though switching on the ignition without the gauge pod (and airbag sensor) connected produces a airbag warning light there after. The airbag light will come on for a few minutes after startup. This can be cured by getting anybody with the VAG diag tool to reset the airbag system.

As a matter of interest, my temp sender was totally missing as well. I was able to make one using a thermistor also sourced from RS. It works like a dream and cost almost nothing.


Hope that helps
Andre

[Dr H]

Cheers gang

[porkkis]

A bit OT but I'm interested in buying the temp display unit that you guys have on your newer cars. Mine is 91 and just has the display in the aircon unit.
Does the instrument cluster temp display use the black 4 pin connector that I have behind my instrument cluster? Connector is a 1 row type. If not, what's this connector for?
Strangely my friends Audi 90 has that connector too, but does not have a single ambient temp sensor AFAIK.