LED Headlight

[Haiderali123]

Hi guys, i’ve purchased a Seat Leon Black Edition 2019 reg. Long story short it was involved in a knock and i had to buy a replacement headlight (LED headlight) I plugged the headlight in today and it didn’t work at all. The wiring was damaged but i repaired it by soldering and then using headshrink. I then decided to test it on the passenger side as that headlight works fine but it didn’t work on that side either. Anyone any ideas? I do know the ballast that i got with it (baught seperate from breakers) is off a 2017 reg car if that matters? I didn’t get any light from it at all, no indicators no drl no nothing as though there’s no power. Tried from both sides as i know my passenger headlight is ok and the wiring is ok. Any ideas please? Attached pics of the light and the ballast i was given. I know the ballast code is wrong at the end as the ballast for the car is supposed to have ‘AJ’ at the end and this only has ‘A’ but would that stop the whole headlight from working? I don’t have the old ballast to check with u fortunately. Thank you

 

[black_sheep]

I’ve replaced headlights, but this came with the ballast attached and fully tested.

A few questions/considerations - ultimately need to determine what is faulty? Light unit, Ballast or both?:

1. Did you purchase the headlight unit as tested/operational (I assume that you got this from a breakers?). Or did you know that it had faulty wiring/potentially not working? If working, I would have sent back for a refund before trying to repair, but appreciate sometimes you just want to get it fixed. Also, did you use a heat sink whilst soldering the wires? LEDs are very easy to fry with excessive heat.
2. Are you sure you have the correct ballast? I would have assumed that the ballast part number would have started 5F0 (ie Seat Leon 5F) where as yours starts 7P5 (VW Touareg). Whilst I appreciate that Seat dip into the VAG parts bin, this would be unusual for an LED lamp unit (in my opinion). An option may be to swap the ballast from the opposite light unit or your old light unit if the same part number? This will identify if light unit or ballast is the faulty if using a know working part.

 

[Haiderali123]

Hi, sorry i should have explained better.

1. I purchased it from a breakers in Netherlands. They said it is a fully tested and working light unit, however the ballast they sent me was from a different car. They said it should be compatible / still work thought they didnt test it. Regarding wiring damaged and heatshrink, i means my wiring loom that connects to the headlight, The actual connector was in bits so i got another connector and joined the wires up and soldered them together. No wiring inside the headlight was touched.

2. Th ballast number is defo 7P5941591AJ. However the one i got sent is the same part number but without the J at the end. Underneath the part number, you will see a HW number. The HW number matches on both ballasts but again im not sure what that means. Yes looks like im going to have to remove the existing headlight and swap the ballast onto this one and then see if it works, Quick question, does the ballast control everything from DRL, Headlight, Flash, Indicators? Because nothing on the headlight works which makes me suspect the headlight is faulty. If the ballast does control all the above then finger could potentially point to the ballast.

Thank you for your reply Black_Sheep. Its much appreciated.

 

[black_sheep]

An explanation about the VAG part numbers is here:

VW Part Numbers Explained

This blog attempts to explain the VW Group part number system. The system used dates back to the 1930s and the original designs created by Ferdinand Porsche. It may look scary, but once you learn the basics, you’ll find that the system is quite consistent and makes things easier to understand...

www.darksidedevelopments.co.uk

AJ is probably just a modification/manufacturer code.

From what I can see, there are numerous part numbers that are compatible, they control all of the lights in the unit (note on EKTA the part is referred to a light control unit) and can be used on either side.

https://m.aliexpress.com/item/2255800772817626.html?gatewayAdapt=4itemAdapt

I hope that this is of some use?

 

[Haiderali123]

Thank you for your reply, so if it is just a modification/manufacture code then surely it should work? I take it the finger points to the headlight then possibly being faulty?

 

[black_sheep]

I’ve been required to chase faults like this for years on aircraft.

You know that the ballast is 100% working on the other headlight - if you have the time, then this will help you to identify which component is faulty through process of elimination. The risk is if the light unit is faulty, it may also damage the ballast I guess.

If the light works, then the ballast is faulty. If it doesn’t work, then it’s the light unit that’s faulty. Hope you get it sorted soon.

 

[Haiderali123]

Black_sheep.... Thank you for your reply. I will check this during the week as my car is off the road for now anyway and then update this post with what the issue is/was. Thank you once again for your feedback and help, its much appreciated.

 

[SteveGSXR600K1]

Ballasts are used on xenon headlights to give them a power surge to start up. SEAT refer to them as modules, and there's one for the DRL and one for the headlight. Not sure, but they may have to be programmed into the car to work. Are you able to swap the module(s) over from your old headlight, or are they damaged?

 

[Haiderali123]

No mate i don’t have the old ones as the headlight was in bits and got thrown away. Do you know if they need programming in possibly? Or do you know where i can find out if they need programming?

 

[SteveGSXR600K1]

I'm not sure if they need reprogramming, but it was a thought as they're modules. Have a look under the 'Sponsors' section and contact East Yorkshire Retrofit Solutions. He'll be able to give you spot on advice.

 

[JoseKaLeL]

Where you got that

Ballasts are used on xenon headlights to give them a power surge to start up. SEAT refer to them as modules, and there's one for the DRL and one for the headlight. Not sure, but they may have to be programmed into the car to work. Are you able to swap the module(s) over from your old headlight, or are they damaged?

View attachment 32852

Where did you get that image manual instructions??? And could you get more of different cars (seat)

 

[SteveGSXR600K1]

Where you got that

Where did you get that image manual instructions??? And could you get more of different cars (seat)

Here you go: https://www.seatcupra.net/forums/resources/leon-mk3-official-seat-workshop-manuals-link.24/

 

[East Yorkshire Retrofits]

It's important that the ballast came from the correct car, from the correct side headlight

If it didn't, it'll require parameterisation before it will work properly

 

[JoseKaLeL]

And how I could know that ???

It's important that the ballast came from the correct car, from the correct side headlight

If it didn't, it'll require parameterisation before it will work properly

I know that I get them from the correct side of each HL but don’t know if the ballast are working or fine

 

[East Yorkshire Retrofits]

And how I could know that ???

I know that I get them from the correct side of each HL but don’t know if the ballast are working or fine

This isn't your only issue. You've done 10% of the work necessary to install LED headlights