Rear Demister Switch

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TheMonzta
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Mon Feb 04, 2008 7:26 pm

My Touring's rear demister switch doesn't illuminate when I turn on my lights. I imagine it should as the rear wash/wipe and hazard switches beside it DO illuminate when the lights are on.

It lights up fine when I press it in to switch the demister on though. I've swapped it for a spare working switch and that's the same. :?
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jcjdavis1
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Mon Feb 04, 2008 7:28 pm

Hi Demist switch does not illuminate,I went through 3 before the penny dropped.There is a mod you can do,try a search.
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TheMonzta
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Mon Feb 04, 2008 7:32 pm

Many thanks for that!

Seems strange not to illuminate doesn't it? It looks strangely odd in the dinge when the others around it are glowing nicely. :?

I'll search for the mod as I want mine to light up.
1991 Honda Civic Twin Cam
1996 VW Golf TDi
2001 BMW 540i Sport

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B7
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Mon Feb 04, 2008 7:33 pm

here it is, Yet to do it myself but it's on the to do list!

http://www.e30zone.net/modules.php?name ... witch1.htm
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TheMonzta
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Mon Feb 04, 2008 7:44 pm

Is that all of it? It seems incomplete. :?
1991 Honda Civic Twin Cam
1996 VW Golf TDi
2001 BMW 540i Sport

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B7
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Mon Feb 04, 2008 9:39 pm

Click on the page 2 at the bottom.
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TheMonzta
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Mon Feb 04, 2008 9:50 pm

B7 wrote:Click on the page 2 at the bottom.
Doh! Didn't see that. :o:
1991 Honda Civic Twin Cam
1996 VW Golf TDi
2001 BMW 540i Sport

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smithy318i
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Mon Feb 04, 2008 11:02 pm

this is a better tech article...

http://mysite.orange.co.uk/smithy318i/Demist2.htm?
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TheMonzta
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Mon Feb 04, 2008 11:09 pm

Hmmm, I don't fancy buggering about with soldering resistors, diodes and all that jazz. :?
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2001 BMW 540i Sport

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smithy318i
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Mon Feb 04, 2008 11:16 pm

you can leave that bit out if you like, it will just not be as bright as the rest of them.

The article in the tech section doesn't tell you that you need to modify the switch.
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Gortour
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Mon Feb 04, 2008 11:23 pm

Never realised the resistor was wrong for the rear window switch, Smithy.
Surely if you're using a hazard switch as a rear window one, the lighting will be the same as the 'proper' hazard.

Does this make the illumination right when it's on as well as when the lights are on?
Last edited by Gortour on Mon Feb 04, 2008 11:26 pm, edited 1 time in total.
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TheMonzta
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Mon Feb 04, 2008 11:26 pm

smithy318i wrote:you can leave that bit out if you like, it will just not be as bright as the rest of them.

The article in the tech section doesn't tell you that you need to modify the switch.
I can certainly do the wiring mods so it at least illluminates and crack the soldering bit of the switch at a later time.

Where can you get the relevent resistors and diodes from?
1991 Honda Civic Twin Cam
1996 VW Golf TDi
2001 BMW 540i Sport

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ian332isport
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Mon Feb 04, 2008 11:33 pm

smithy318i wrote:The article in the tech section doesn't tell you that you need to modify the switch.
That's because it's only the fitting instructions :D
If it aint broke - Modify it...
TheMonzta
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Tue Feb 05, 2008 10:59 pm

TheMonzta wrote:
smithy318i wrote:you can leave that bit out if you like, it will just not be as bright as the rest of them.

The article in the tech section doesn't tell you that you need to modify the switch.
I can certainly do the wiring mods so it at least illluminates and crack the soldering bit of the switch at a later time.

Where can you get the relevent resistors and diodes from?
Just bumping this one. Where can I buy the resistors and diodes needed for this job?
Last edited by TheMonzta on Tue Feb 05, 2008 11:05 pm, edited 1 time in total.
1991 Honda Civic Twin Cam
1996 VW Golf TDi
2001 BMW 540i Sport

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ian332isport
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Tue Feb 05, 2008 11:02 pm

Maplin, RS or Farnell.
If it aint broke - Modify it...
TheMonzta
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Tue Feb 05, 2008 11:11 pm

ian332isport wrote:Maplin, RS or Farnell.
Cheers for that, I'll see if I can find their websites. :D
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1996 VW Golf TDi
2001 BMW 540i Sport

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smithy318i
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Tue Feb 05, 2008 11:14 pm

I wouldn't bother with just buying a single resistor. If you can source a second hazard switch, you can solder the two 150ohm resistors in series to achieve the correct illumination.
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ian332isport
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Tue Feb 05, 2008 11:19 pm

smithy318i wrote:you can solder the two 150ohm resistors in series to achieve the correct illumination.
Parallel perhaps. 300 ohms is going to make it very dim indeed. I use a 100 ohm resistor when I do it.

Ian.
If it aint broke - Modify it...
smithy318i
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Tue Feb 05, 2008 11:22 pm

Erm... Yes sorry. :o:
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