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HID's fog lights

Discussion in 'A3/S3/Sportback (8P Chassis)' started by k9audi, Sep 13, 2011.

  1. k9audi
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    k9audi NITRO

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    Am thinking of fitting HID kit for the fog lights and was wondering if it would cause any problems in regards to any electrical faults?
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  2. Cruiser89
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    Cruiser89 <span style="color: blue;"><b>Advanced In Car Tech Site Sponsor

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    If your car is due an MOT next year I wouldn't bother. Would be a fail unless you have washers and ballasts. Also heard that fitting some HIDs can cause problems to the rear wiper due to the bigger load on the line.
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  3. k9audi
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    k9audi NITRO

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    I know if you have the hid kit for your front headlights that causes the wiper motor to burn out but I wasn't sure about the fog lights
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  4. Adamantium
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    Adamantium Member

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    None of that makes any sense!

    HIDs require less current than conventional incandescent bulbs.

    I had HID fogs on my SLK, I bought them as the fogs were used as the get you to your door light and looked nice when the whole car was lit up at the front at night.

    Strictly speaking the colour temperature of HIDs is less than optimal for increasing visibility in fog, so ideally you should not fit them for function purposes.

    The yellower stock light bulbs produce a light that is more penetrative into fog and therefore better for visibility.

    If there is a can detection signal on any lighting circuit, it looks for consistent current drain. It will detect an HID (if not expecting it) because the current drain on start up is high then it drops below the expected level once the HID ignites. If you have a blown bulb detection function, the power to the bulb will be cycled on and off until it sees the correct current draw. This causes the bulbs to flash.

    Fogs are never expected to be HID by the manufacturer for the reasons I stated above, so you can't recode to make them work. You can fit an inline inductor or an in parallel capacitor. This smooths the current flow that the circuitry detects so it thinks the HID is a regular bulb. You can buy these on ebay for £10 if thats what you want.
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  5. Ash187
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    Ash187 Audi Retrofitter

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    no problem fitting HIDs in fogs... excuse the crappy iphone pic but:
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    Mate get the facts straight before advising others... its misleading and too far from fact! HIDs have not affected rear wipers! aftermarket HID Ballasts affect the front wiper motor as they ground in the same area and shorts out the wiper motor.
    how many cars have you seen with washers on fogs??

    what he said is perfectly right... HIDs in fogs are useless for actual foggy conditions as you can't really see much with them on in foggy conditions... but they do look nice when matched up like mine and compliment the bi-xenon HIDs i have :)
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  6. k9audi
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    k9audi NITRO

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    Thanks for the input Adam
    Ash yeh you got that right the fog lights looks lot better with hids, so you reckon the cheap hid h7 kit from ebay is ok for the front fogs?
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  7. Ash187
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    Ash187 Audi Retrofitter

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  8. Adamantium
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    Adamantium Member

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    I've used cheap HID kits for years.

    Many say the chinese made kits fail much quicker.

    They are right. I've had three ballasts go on my wife's CRV, but at £10 a shot I don't really care. You can now pick up a full HID kit for less than a decent incandescent bulb.

    Please don't be a moron and go for high colour temperature.

    The best colour temperature is circa 4150. The closest aftermarket people get to that is 4300. These will allow you see more and will not dazzle other drivers if used with a proper projector lens.

    When retrofit HIDs first came out a load of idiots went for the highest colour temperature they could in search of the OEM look blue tint. All OEM cars have 4100K bulbs made by philips or osram etc. (Some now are going to 5000 because of marketing pressure from the people who think the aftermarket kit high numbers are the best).

    There is a lot of science that explains the reason for the blue/purple tinge you get but to summarise it is due to the different speed of travel of the different frequencies that make up white light travelling through prismatic lenses. You tend to get a bluey purple glint at the cut off lines of the light.

    When cars having these go over bumps the light beam that you see moves relative to your eyes so you catch that little bluey glint as that part of the beam passes your eye making it look like it flickers blue.

    Aftermarket rubbish is marketed to people trying to achieve this look and they do it by going for bluer or purpler colour temperatures. The combined problem of these is that blue light is higher energy and as a result it is much more tiring on your eyes. Get your eyes used to the dark and then look at a bright blue light. The image will stay on your retina far longer than if you look at a red or even green light. Because of this your eyes struggle at night when viewing the road, as do those of oncoming drivers.

    The worstg part is the bleed you get around the edges of the beam. If you have decent prohector lenses even with an aftermarket HID you should get an excellent cut off line. The higher colour temp you go to, the less sharp this line is until you end up with a fuzzy haze of light that reduces in intensity gradually rather than a nice focussed beam.

    This gives poor road lighting performance and again is a real problem for dazzling oncoming drivers.

    In short, order the 4300k they are better in every way.
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  9. danb986
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    danb986 In awe of VCDS

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    Adamantium has got it right.
    I put some aftermarket HID's on my wife's old Fiesta when they first started becoming available and I took them out after a week. The headlights were just the standard reflector type and the light scatter was awful! I tried them in my Mk4 Golf, and they actually worked quite well, but again I only left them in for a week or so.
    These were 6500K and although they aren't the best colour temperature for improve visibility I actually found them really impressive and far better than the halogens. The light cut-off in the Golf was excellent and I never got flashed, but I could see them causing trouble in the future so I took them out as my wife drove the car too.

    Ash, they look really good. I know it's probably just how they photograph, but they look frickin' bright! I swear I can still see them when I blink :cool:
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  10. Ash187
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    Ash187 Audi Retrofitter

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    I hate it when people fit HIDs into non projector housings! all of my HID kit installs have always been in projector housings as not only does it not break the law and blind everyone it also looks good!

    yes the pictures came out crap but thats the lack of proper ISO adjustment and exposure on the iphone camera... i have just got the other half a decent camera so i will try and get some pics with that and see if it comes up any better.

    oh and yes as my sig says my HIDs are 8000k... but not had an issue with them at all either with public or police as they are OEM housings and ballasts, just replacement bulbs.
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  11. andi1
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    andi1 WWW.APR-REMAPS.CO.UK

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    Get some 3000k yellows in there or 4300k pure white they cut through the fog very well we can do them in a special earth canbus kit to suit the a3

    thanks
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  12. Adamantium
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    Adamantium Member

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    I wouldn't use any kind of HID for fog applications if you want to use them for seeing.

    if you just want them to look good next to the stock hids, then fit 4300. Personally I think correctly functioning front fog lights are next to useless anyway, so you may as well get them to look nice!
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  13. danb986
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    danb986 In awe of VCDS

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    That's a good point actually, I can't think of a time when I've turned them on in thick fog and it's helped in any way.

    I really like the look of matching HID's in the fogs (especially after seeing the pics of Ash's) , but I'd just get pulled over the whole time and I can't be bothered with that. I know loads of people have their front fogs on and have never had a problem, but I know if I turned mine on for 10 seconds I'd get stopped by the police. It's just how my luck goes.

    I totally agree with you Ash. HID's in non-projector headlight housings are not a good move.
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  14. Ash187
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    Ash187 Audi Retrofitter

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    Lol i have been pulled over twice in 8 years for having my fogs... once was even by the undercover 'feds'.

    i usually have them on at night when driving down a motorway to get people that are driving like granny's out of my way! there is something mean about the look of my car when i have the HIDs on and going like a rocket up behind someone that makes them get out of the way quickly :ninja:
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