I switched on the headlights and none of the the dashboard lights worked.
After checking the fuses, I suspected the dimmer switch (61 31 8 353 507).
Here are a couple of images of the switch...
At first sight, it looks like it will be very difficult to repair without breaking it, but there is nothing I'll not do to try and save £50!!
Disassembling the switch is not too difficult if you have the thin bladed tools to lever the plastic apart without breaking it...
Care must be taken removing the circuit board as it if firmly secured by plastic tabs.
The switching module MUST be in the position shown to remove it as the spring tabs (to lock it in the sidelight and headlight positions) are able to be released.
Once the switching module has been released, the whole switch can be disassembled...
and the dimmer module can be removed...
and disassembled...
(the image was taken AFTER the repair)
Although it was not the cause of the fault, the black part of the dimmer module had broken. The cause of it breaking was probably the driver forcing the switch too far clockwise or anti-clockwise. I repaired it with some superglue...
The cause of the fault was a broken resistance wire...
The maximum resistance I was able to measure was 19 Ohms, so I estimate the original resistance to be 20 Ohms.
I repaired the fault with some solder and filed it so it was flush with the spring and tested for continuity.
After reassembly, I tested the switch for continuity between terminals 6 & 8. Fully dimmed (anti-clockwise)..
and max brightness (fully clockwise)...
The only difference between the original and the repaired switch is that minimum brilliance will be slightly brighter than before
- and I still have £50 to spend on fuel
Repairing Headlight Dimmer Switch
Repairing Headlight Dimmer Switch
Last edited by pingu on Tue 30 Sep, 2014 23:04, edited 1 time in total.
Pingu
Re: Repairing Headlight Dimmer Switch
Nice write up, if the resistance coil is too far past it you can also put a jumper wire across the pins as shown below. This just puts your dash lights on at all times.
Re: Repairing Headlight Dimmer Switch
Excellent write up. It must be the fun of taking things apart, finding the fault and then a solution that makes owning an older car fun.
The latest cars will be a pain to work on later in their life.
I have heard stories of one particular sports car that has a V8 that to change the back pair of spark plugs the engine has to come out, at least the plugs don't need changing for 80k miles.
The latest cars will be a pain to work on later in their life.
I have heard stories of one particular sports car that has a V8 that to change the back pair of spark plugs the engine has to come out, at least the plugs don't need changing for 80k miles.
Brian
3.0I Topaz Blue
2000 E36/7 Z3 3.0i
2016 F31 335d
2015 F21 118i
3.0I Topaz Blue
2000 E36/7 Z3 3.0i
2016 F31 335d
2015 F21 118i
Re: Repairing Headlight Dimmer Switch
It becomes a problem when the electronic modules are gel-filled, but yes IT IS FUN .Brian4 wrote:Excellent write up. It must be the fun of taking things apart, finding the fault and then a solution that makes owning an older car fun.
The latest cars will be a pain to work on later in their life.
Pingu
- lordhelpus
- Joined: Sat 14 Sep, 2013 09:46
- Posts: 128
- Location: Tax Exile
Re: Repairing Headlight Dimmer Switch
That's just the kind of thing that makes this site what it is...................well done pingu....top job.
1997 2.8................ Montreal Blue
Re: Repairing Headlight Dimmer Switch
Brilliant write up and photos Pingu. Well done, great ingenuity and a tank full of fuel into the bargain
Re: Repairing Headlight Dimmer Switch
Brilliant, make sure it goes into the knowledge base! Cooper
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- Joined: Sat 27 Jul, 2013 23:01
- Posts: 51
Re: Repairing Headlight Dimmer Switch
Brilliant write up. To be honest, i hadn't realised that turning that knob made the dash lights dim Just tried it after reading this superb guide.
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- Joined: Sat 18 Jun, 2016 10:35
- Posts: 296
- Location: Blaenau Gwent South Wales...
Re: Repairing Headlight Dimmer Switch
thanks for sharing this on my list of things to do.. hopefully i will get around to doing it today...
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- Joined: Fri 14 Aug, 2009 10:24
- Posts: 907
- Location: Houghton-Le-Spring
Re: Repairing Headlight Dimmer Switch
Great write up and many thanks for sharing, there was a repair on YouTube but the light wouldn't dim, where this repairs it to original spec.