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CrazyDave

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

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That's another one for the list of mods. I'll be in there anyway fitting a "lights on" buzzer.

Cheers Dave :clap:

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How do you know if the added fuse has prevented a short. Would the headlight switch just stop operating or will it continue to work ? How will you know when to change the "added" fuse is what I am trying to get at :)

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How do you know if the added fuse has prevented a short. Would the headlight switch just stop operating or will it continue to work ? How will you know when to change the "added" fuse is what I am trying to get at :)

 

Like anything with a fuse, when the fuse blows due to a short, the circuit is broken and the switch will stop working. :D

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Like anything with a fuse, when the fuse blows due to a short, the circuit is broken and the switch will stop working. :D

 

No, the switch doesn't stop working - except for the internal illumination!

 

How do you know if the added fuse has prevented a short. Would the headlight switch just stop operating or will it continue to work ? How will you know when to change the "added" fuse is what I am trying to get at :)

 

The fuse is protecting the earth wire in the headlight loom solely used for the switch illumination. It protects against a dash fire or melt down of the headlight loom. It plays no part in the sidelights & headlights.

 

The light symbol illumination not working means two things, a short ie, the fuse has blown or the little green bulb inside the switch has blown but the fuse is OK.

 

If the fuse has blows, then yes the switch will continue to work the Corrados lights but it may be at risk due to a faulty switch or loom problem. Advisable to check the switch soonest / headlight wiring loom and establish what has happened.

The most likely cases are:

- New replacement switch is faulty, should have carried out the pre-check in this topic.

- Internal collapse mechanically of the switch leading to the crossing of 12 volts with the earth.

- Using partially broken switch which mechanically squews the switching plate inside so 12 volts contacts the earth internally.

 

If it is the small green bulb inside that has blown, the switch will continue to work the sidelights & headlights normally.

 

.

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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

 

golf switch just doesn't have the 'ignition on' illumination the corrado one does (think it still has the sidelight warning illumination though), like you say, it's a direct swap otherwise, but it's not like it's hard to find the switch in the dark :lol:

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i replaced the headlight switch in mine with the Mk 2 one - doenst look great but also not too bad either. I have a Mk3 switch (dial type) which is much larger but i'm trying to figure out a way of mounting this neatly but with easy access,in the dash, but more importantly how to wire it in!

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Nice posts about the DIY preventions on the headlight switch and loom fires. It gave me new ideas on how to deal with such things in order to use or to make it work in the near future. Keep it up guys!

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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

 

 

 

 

Thanks very much for this, very usefull. Have just bought a golf one for a fiver! Much better than £50!

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I only have 5Amp fuses ATM. is that ok for this? Or too much?? I think that if a short occurred, a 5A fuse would blow itself so that'll do the job, won't it?

 

Thanks for the DIY :grin:

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The wires may fry a little before that blows depending on how the electrical short develops. Best low as possible ie, 200mA ideally (allows for cold start current). There's only a mini filament bulb electrical current thro' the fuse normally. ie 1.2 watts = 85mA.

 

I've eventually changed my 3 amp down to 1 amp fuse like the cars' fuses but that's the lowest I can find to fit the type of fuse holder I used.

 

.

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hm, I realised (may I have read the thread first? :lol: ) that this wire is only for headlight switch's inner bulb, I mean, the one that enlightens the "bulb" picture, isn't it?

 

well now, this light doesn't work in my switch, so I think I've done a pointless mod :brickwall:

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hm, I realised (may I have read the thread first? :lol: ) that this wire is only for headlight switch's inner bulb, I mean, the one that enlightens the "bulb" picture, isn't it?

 

Bottom of p1 - Schematic - two green circles are the bulbs. Pin 31 is the connection to the wire you have modified.

 

well now, this light doesn't work in my switch, so I think I've done a pointless mod :brickwall:

 

You have not understood the mod. The switch internals can have/has the electrical shorts to the wire on pin 31 of the switch, irrespective of the bulb being blown.

 

Congratualations, your Corrado now has one less fire risk :)

 

.

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hm, I realised (may I have read the thread first? :lol: ) that this wire is only for headlight switch's inner bulb, I mean, the one that enlightens the "bulb" picture, isn't it?

 

Bottom of p1 - Schematic - two green circles are the bulbs. Pin 31 is the connection to the wire you have modified.

 

well now, this light doesn't work in my switch, so I think I've done a pointless mod :brickwall:

 

You have not understood the mod. The switch internals can have/has the electrical shorts to the wire on pin 31 of the switch, irrespective of the bulb being blown.

 

Congratualations, your Corrado now has one less fire risk :)

 

.

 

I should read things twice or more :lol: :lol:

 

 

however, my headlights work OK with this wire cut :|

 

and now some bulbs (climatronic one, which is connected to ignition) and (mfa bulb, connected to ignition as well) don't work. It looks like everytime i fix something, another thing goes wrong :(

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Great thread by the way.

I bought a switch off a guy on the corradonet that almost cost me my car :censored:

Fitted it on the morning of the mot,then smoke starts flowing out the dash,luckily after blowing air at it the small flame blewout just as it was about to really get going.

 

So no more second hand dodgy electrics for me,and getting a custom made loom aint cheap either.

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That was a nice DIY in Headlight Switch and Loom Fires prevention. I hope that many kinds of threads around this forum and others would have this kind of DIY. A different DIY that will help us prevent to do damage or to inflict many things to act up in our car. Keep it up!

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Long story short....... last week driving along, thought I could smell smoke. Stopped the car and discovered the headlight switch had stopped working . Turned out the brown earth wire had burnt out. I was very lucky that it didn't start a massive fire!

 

Now the car has a new switch and DIY safety mod fitted. ('tandino' fitted them)

 

I was luuuuuuccccckkkkyyyyyyyy.

 

Get the mod done boys & girls.

 

:salute:

 

4956817290_6874612676_z.jpg

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Long story short....... last week driving along, thought I could smell smoke. Stopped the car and discovered the headlight switch had stopped working . Turned out the brown earth wire had burnt out. I was very lucky that it didn't start a massive fire!

 

Now the car has a new switch and DIY safety mod fitted. ('tandino' fitted them)

 

I was luuuuuuccccckkkkyyyyyyyy.

 

Get the mod done boys & girls.

 

 

Very lucky indeed...I recall wasnt long ago you were asking about getting a fire extinguisher on previous posts :D

 

As soon as I discovered this mod. It shot to the top of my list of things to do as a prority over everything else. For a few pounds to get the inline fuse in its a no brainer.

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Very lucky indeed...I recall wasnt long ago you were asking about getting a fire extinguisher on previous posts :D

 

 

:D Yes that was me. And no, I still don't have a fire extinguisher.

 

I can be such a dumb*** sometimes. :roll:

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I realize I'm kinda new here, but I was about to do this on my car and realized a slight problem with these instructions. It's a brilliant idea, but the fuse is being put in the wrong place. If you put it that close to the switch, it will prevent a fire in the case of a short inside the switch. But, if there is a short inside the wire harness further back inside the car, then the fuse won't blow. I made a quick Microsoft Paint picture showing what I mean. In the picture below, with the short shown, the fuse at A isn't going to blow because the current would have a path that would bypass that fuse. However, a fuse farther up the wire, at B, WOULD blow, preventing a fire. I know the main cause of this problem is a short inside the headlight switch; but if this is something you have been meaning to do, why not put the fuse a little farther up the wire and prevent another possible (however unlikely) cause for a fire?

 

HeadlightFuseShort.jpg

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Deep inside this thread on page 2, 2nd & 4th posts is hidden this. Note the fuse holder position.http://the-corrado.net/.archive/forum/download/file.php?id=22601&sid=f1ce2755ae86cd41b9a3b89efdd89983&mode=viewBut If you are going to worrying about this, then start worrying about all the unprotected looms prior to the fuse box. The fuses protect control units, etc., not the looms.

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Deep inside this thread on page 2, 2nd & 4th posts is hidden this. Note the fuse holder position.http://the-corrado.net/.archive/forum/download/file.php?id=22601&sid=f1ce2755ae86cd41b9a3b89efdd89983&mode=viewBut If you are going to worrying about this, then start worrying about all the unprotected looms prior to the fuse box. The fuses protect control units, etc., not the looms.

 

I hadn't even noticed the picture while reading through the thread. And it's not so much that I was worried about it, but it's the kind of thing that if you're adding the fuse anyway, why not add it as far up the wire as you can?

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I hadn't even noticed the picture while reading through the thread. And it's not so much that I was worried about it, but it's the kind of thing that if you're adding the fuse anyway, why not add it as far up the wire as you can?

 

You don't happen to own shares in a company that manufactures fuses do you... ;-)

 

I keep meaning to do this mod, as mods go it looks quite simple and more importantly beneficial to the longevity of my C!

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