NCT - lights

ittakestwo

Car failed NCT on front lights. He said he could not get a reading for the lights. The lights go on but the casing they're in is very dirty. He said possibly if this was cleaned he could get a reading. I rang my macanic and could not get through so looked up on Youtube how to clean them. Surprisingly you can clean them without taking anything off. One tip was to use tootpaste. I did this and they came up much clearer.

Anybody been in this position on failed lights before? Can you just clean them yourself and they will get through next time?

Atlantic Dawn

Toothpaste can temporarily fix them, I'd recommend instead getting a kit which will do it using a drill and seals the results...

https://www.halfords.ie/motoring/car-cleaning/car-cleaning-kits/autoglym-headlight-restoration-complete-kit-179824.html

As regards passing or failing without seeing a photo it's hard to tell, if distortion is just outside they should pass after repair.

ittakestwo

https://www.boards.ie/discussion/comment/119027970#Comment_119027970

20220507_121224.jpg

So did one light quickly. The other light is not done. There is a clear difference. I will do them both again more thoroughly when I have more time. But hoping this will be enough.

Atlantic Dawn

Yes very noticeable difference. I don't think there's any distortion on the inside of the glass so that should do it.

I found with the toothpaste that it came out great but after a couple of months it went bad again, the kit gave me well over a year where they still looked like brand new.

PsychoPete

Probably best to get them wet sanded and polished properly. Make they get good protection afterwards so they don't go yellow again in no time

ittakestwo

So I did retest this morning and passed. Worth noting for anyone who fails on this it is something you can easily fix yourself.

Cass

Mine did't fail but they were looking tatty so I decided to be proactive and bought the headlight restoration kit. There are a few, and I have a couple including Meguiars and Holts, and each kit contains something the other doesn't.

The basics are:

• Sand paper (from 600 to 2500/3000 grit)
• Sanding block/drill attachment
• Plastic rubbing compound
• Cloth
• Sealant (not available in all kits).

When sanding have a basin of soapy water. Doesn't matter which soap its more for lubricant. Start with the lowest grit in the pack (say 600). Move left to right ONLY and continue until the sandpaper moves freely. Keep dipping in the soapy water as you do so, and for this reason its always a good idea to mask off the area you're intending to work on so as not to damage bodywork.

When you're done with the 600 move onto the next sandpaper, say 800. Now use this in a "top to bottom" pattern. Again constantly dipping/rinsing in the soapy water.

Keep doing this and changing direction for each grain of sandpaper. Never go the same direction when changing sandpaper. You want each finer level to "cut across" the previous ones while taking out the micro abrasions caused.

Once the sandpaper is moving freely, almost gliding, and you're happy the light is done rinse the headlight off well and dry with a microfibre cloth. It took me about 35 to 40 minutes per headlight. Once dry you move onto the compounding.

At this point you're headlight will be milky white. It'll look terrible and you'll wonder if you've fecked it all up, don't worry you haven't.

The Meguiars kit uses a product called Plastic X. You apply it to the applicator pad and again work in left to right then top to bottom movements. Keep going until the compount almost goes clear. Once done wipe with a microfibre. Ifthe headlight is completely clear then move onto the sealing, if you're not happy then repeat the compound set again.

Once its done you need to seal the headlight as the sanding will have removed any UV protection the headlight lense had. Some kits have this in it. YOu spray the sealant onto the headlight. Give it about 10 seconds then wipe with clean microfibre cloth. It'll feel tacky at first but become smooth as you wipe. Keep changing the cloth so its always a clean part wiping. Don't try to use the same part as it'll leave streaks or no do it correctly.

Some people choose to use a clean laquer rather than a sealant. It'll last longer, but if it goes wrong you'releft having to sand off all the laquer and starting again. The sealant is easier to apply, but won't last as long, however you need only re-apply the sealant eveyr few months to maintain the clarit.

Before pictures of my headlight

After pictures