Headlight switch and loom fires.....DIY prevention

[Supercharged 2]

Sticky? Get ur finger out! Should have been done in 2005

 

Hi Chris - well that 2005 thread was actually stickied and I will leave it for now like that.

[RW1 0]

Hi Steve,

 

This one would be better now to sticky as it pulls in all the info and the other is referenced by Dave's first posting.

 

Just add this one, don't I think there's anything else lying around???

viewtopic.php?f=19&t=19701

 

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[big ben 10]

what a thread, will be doing this very soon on the VRT

[Philmo 0]

This sounds a little like the old Ford V6 in Scimitar self combusting scenario caused by interference fit petrol feed pipe in carb casting working loose, filling the Vee with fuel and woosh! Standard solution - refit using Araldite.

 

Say Dave - does this apply to the later switches also?

[JMC 0]

Just get the standard 3mm 12V led's from Maplins mate. Most of the switches are 12v (apart from the window switches) and the headlight one definately is.

 

Too dim, tried that type first, miles dimmer than the standard little green bulbs. Tried Maplin's 3 volt ones, again at the time not bright enough. Needs a pair of bright LEDS. LEDs were green from maplin, part number N30BY http://www.maplin.co.uk/module.aspx?moduleno=45930

 

End up with a metal film resistors from RS Spares part number 144-295, 2.7K ohm, Metal Film 0.125w.

Now superceded http://uk.rs-online.com/web/search/sear ... &x=29&y=15

(You need this physical size to get the resistors in without fouling the mechanics.) Maplin at the time didn't offer 0.125w resistors. And note the two small insulating sleeves in the photo on page 1 of my postings.

 

The LED lens for the ring illumination need "damping" or it looks unbalanced so I painted a black blob of touch-up paint on the crown of the lens. This is the LED furthest from the dimmer control. Don't bother with paint on the other as it not as transparent and it needs the direct beam of the LED onto it.

 

The fuse I used was a 1 amp standard blade fuse like the Corrado's type. Dave's 200 mA fuse will work just as well. I tested the 1 amp fuse on a length of same wire across a battery's terminals direct. Fuse blew, wire - no damaged found, it was instant.

 

My switch operates a BRMotorsport headlight loom. It is always stone cold.

 

Sticky? Get ur finger out! Should have been done in 2005 :lol:

This topic has it all in one spot now for the headlight switch problems.

No excuses now!!!

 

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Strange, never had a problem with them for the early headlight switches (and I've done loads of them). Had to take the existing green filter in the switch out though, and with the late headlight ones it pays to dremel down the opaque plastic below the icon as that could be causing it to look dim. Also the led's are very critical on alignment - a few degrees off and they look dim. If you can be bothered to you can get 120 degree dispersed ones, but they are normall low voltage and need resistors.

[CrazyDave 0]

This sounds a little like the old Ford V6 in Scimitar self combusting scenario caused by interference fit petrol feed pipe in carb casting working loose, filling the Vee with fuel and woosh! Standard solution - refit using Araldite.

 

Say Dave - does this apply to the later switches also?

 

Seem to be a problem on all the switches, even brand new dealer ones sometimes :shock: . So best to test them out as per RW1's guide before fitting :)

[Supercharged 2]

Yeah, I think the issues with LEDs is the light is very directional with most having a 15 degree viewing angle...

 

JMC - any chance you have a list of part numbers used for the switch LEDs??? Did you also say the late windows switches were not 12V?

[JMC 0]

Yeah, I think the issues with LEDs is the light is very directional with most having a 15 degree viewing angle...

 

JMC - any chance you have a list of part numbers used for the switch LEDs??? Did you also say the late windows switches were not 12V?

 

Green leds in Maplin are WL33L. However you might be better looking for ultrabright low voltage ones on ebay. They are much brighter but will need to be fitted with a resistor.

[davidwort 0]

factory fit window switches run to the window control unit so don't need to be 12v as don't feed the motors directly, I assume the updated roof electrics are similar, whereas the early roofs are a direct power switch to the motor with no auto features.

[RW1 0]

Yeah, I think the issues with LEDs is the light is very directional with most having a 15 degree viewing angle...

 

Yup, was part of the problem in the late version switches I have. Hence the route with the Maplin one I posted earlier. The more directional, the more problematical the illumination as the switch cover symbol and "ring" move relatively to the LED beam. Right for one switch position, go to the other end of the switch rocking, the illumination has disappeared.

 

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[Jon_vr6 1]

Previous owner of my car installed a MK2 golf headlight switch after the original one broke fingers crossed havnt had a problem with it yet and doesnt look too out of place :D

[VWVW 1]

Previous owner of my car installed a MK2 golf headlight switch after the original one broke fingers crossed havnt had a problem with it yet and doesnt look too out of place

 

 

Is the mk2 golf headlight switch a straight swap with the corrado. Does any one know if it needs to be modified ?

 

cheers

[dragon green 4]

Previous owner of my car installed a MK2 golf headlight switch after the original one broke fingers crossed havnt had a problem with it yet and doesnt look too out of place

 

 

Is the mk2 golf headlight switch a straight swap with the corrado. Does any one know if it needs to be modified ?

 

cheers

 

Sraight swap :D

[Jon_vr6 1]

whether the mk2 headlight switch will stop the loom fire is another problem :shrug:

[RW1 0]

Not really. Its VW's way of fusing circuits that leads to the problem. The 12 volts to the switch no matter which wire input are not fused. This earth wire if made to contact inside a switch....... Mk2 switch may be more robust but if it does fail, effect will be the same. For a few bob, it's peace of mind.

 

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[Philmo 0]

This sounds a little like the old Ford V6 in Scimitar self combusting scenario caused by interference fit petrol feed pipe in carb casting working loose, filling the Vee with fuel and woosh! Standard solution - refit using Araldite.

 

Say Dave - does this apply to the later switches also?

 

Seem to be a problem on all the switches, even brand new dealer ones sometimes :shock: . So best to test them out as per RW1's guide before fitting :)

 

Don't want to push it - but are you set up for testing on sat? :ignore:

[dragon green 4]

Took some pics of the headlight switches,sorry about the quality,not the easiest of subject matter !

bottom is Mk2 golf

middle early Corrado

top late Corrado

All fit the Corrado

Took pics of the rear of the switches,the top 2 (Corrado) are exactly the same !

the bottom one (Golf) has 2 pins missing, but still works on the Corrado.

Iam sure someone will be along to tell us if its a good or bad thing

[Jon_vr6 1]

I darent look at the back of mine incase its been bodged :confused4:

[Jon_vr6 1]

Going off the pic on page 1 looks like on a mk2 golf switch that the wire that Dave is cutting wont connect to a pin because there isnt one

[dragon green 4]

Going off the pic on page 1 looks like on a mk2 golf switch that the wire that Dave is cutting wont connect to a pin because there isnt one

Yep thats the earth wire !

Perhaps thats why the Mk2 doesnt suffer the same problems as the C .

Cant remember if the Golf one illuminated or not,cant try it g/f has borrowed the car :(

[Jon_vr6 1]

my used to illuminate now it doesnt think its the bulb

[krnau 0]

shouldn't fuse be placed on the positive-side wires instead of the negative one? Just to ask!

[RW1 0]

The point of the fuse in the earth wire is to protect due to an "unusual" failure in the switch. ie. the switch goes mechanically u/s and leads to a short or as stated can be supplied new with a soldering fault internally (numerous have occurred that I know of since the first I came across in 1997).

 

The headlight fuses are after the headlight switch in the circuit. VW assume loom wiring will be generally safe once installed. By splitting the circuits after the switch, more of the circuits continue to work if one unit in the circuits fails resulting in a short circuit. ie. if a headlight bulb shorts on failure, then the other headlight bulb continues to operate.

 

To put a fuse ahead of the switch means a large fuse rating ~40 - 50 amps. With a fuse that size, the earth wire would be toast before the fuse blew or would probably delay the circuit protection and some damage would result to the loom between the headlight switch and the fuse relay panel.

 

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[krnau 0]

perfect, just what I needed to know :) thanks! I'll be doing it shortly :)

[VWVW 1]

I have just done this mod today…and got one of my index finger burnt in the process :( So be careful with this !!! Never done soldering in my life :) Glad I got it done. Guess I wont be attempting the LED mod version of this as I dont think I can afford to get any other fingers burnt in the process :)

 

On the VR6 there wasn’t much “extension” for me to work on once I've disconnected the headlight switch.

 

 

So had to take all the lower trims out to get to it from the bottom up

 

 

The finish article.

 

Have to say thanks to Crazy Dave for this mod. Otherwise would have never known about this issue :D