How I am fixing the led stripe in the door....

[jaypoto]

Need a little basic 101 electrical advice so figured I would post here..

Long story short - My white led drivers side door stripe burned out on my Alltrack. I tracked it down to the small Hella led chip board failing. If you didnt already know VW plastic welded this all to the door and it's not serviceable other than to replace the whole door card. Eff that, I am going to fix this single led!

I purchased a used drivers side door card which was advertised for an Alltrack. I extracted the led chip board from that one by melting away the surrounding plastic with a hot knife. I plugged it into my door card harness and tested and lo and behold it's a God Damn red led from a GTI WTF lol!

My last resort since I had everything apart was to see if I could de solder the white led on 1 chip and re solder it to the other which I failed at and destroyed both lol.

Now my next step is to just purchase a single white led and plug it into the harness which is all I would need to get the led door stripe working again.

Need a recommendation on what type of led to purchase. I ask because the Hella chip that came out of the car is a little more advanced than a single led possibly to work with the dimming option on the mfd, but not sure. Will a basic single white led with 2 wires +/- work in this case? If not any recommendations on what to purchase, I don't mind soldering something if I need to.

 

[gixxerfool]

any pics? I would be able to tell better or at least give better recommendations to see what you’re working with

 

[jaypoto]

any pics? I would be able to tell better or at least give better recommendations to see what you’re working with

I will upload one tonight, thanks.

 

[jaypoto]

I ordered a bag of these single leds, and they work when plugged in. Next hurdle is shaving them down to sit flush with the plastic light bar. I already installed and everything works but the light has a small hotspot through the plastic light bar - proof of concept! Will have to either get a brighter led or work on flush mounting them better to get the led lighting consistent. Overall happy with the results!

 

[jaypoto]

any pics? I would be able to tell better or at least give better recommendations to see what you’re working with

Grabbed a pic of the ruined led chip boards front and back.

 

[gixxerfool]

Hard to tell from this pic, looks like a PLCC-4 LED. Pretty common for these type of applications. Pretty low forward voltage about 3.0 bolts or so. Depending on your soldering skills, those boards are salvageable as they sit. If you want to use a more typical LED, you would need to match the voltage pretty close. If it’s a higher than typical voltage, that may present problems depending on the difference. If it were me, I would match it an replace it. It’s cleaner and easier. The light dispersion pattern for the PLCC-4 is going to be unique due to its design. So if you try to use, say a Piranha instead, it will work with some light loss most likely.

 

[jaypoto]

Hard to tell from this pic, looks like a PLCC-4 LED. Pretty common for these type of applications. Pretty low forward voltage about 3.0 bolts or so. Depending on your soldering skills, those boards are salvageable as they sit. If you want to use a more typical LED, you would need to match the voltage pretty close. If it’s a higher than typical voltage, that may present problems depending on the difference. If it were me, I would match it an replace it. It’s cleaner and easier. The light dispersion pattern for the PLCC-4 is going to be unique due to its design. So if you try to use, say a Piranha instead, it will work with some light loss most likely.

sorry about the pics! That plcc-4 led looks spot on, very bright focal point. I am going to order a set and see if I can salvage the boards.

I updated the previous post to state that the new led does in fact dim. Why the need for the fancy board then?

 

[gixxerfool]

sorry about the pics! That plcc-4 led looks spot on, very bright focal point. I am going to order a set and see if I can salvage the boards.

I updated the previous post to state that the new led does in fact dim. Why the need for the fancy board then?

The board Carrie’s the resistor to cut the voltage coming in from the module. Most modules output at 5 volts since the different color leds have different voltage requirements they need to shunt the incoming voltage to the proper working voltage level. There’s likely a capacitor on there as well to clean up the voltage signal.

 

[2018gti]

Fun fact about that LED in particular.. it can be red or white depending on the polarity. It sounds crazy but take a look:

That’s probably why you saw it light up red even though it was supposed to be an Alltrack door.

 

[Cuzoe]

You would need to have an LED that lights up both colors. All LEDs are not like this. Which is not to say for sure this one isn't, but I would be surprised if it was.

I suppose if you have a spare LED you can just connect the wires the opposite way, to the LED directly, as a test. But I don't know if I would do that on the PCB. You don't know what might happen.

At one point, before I decided to go full RGB, I was looking at adaptations and coding of the BCM on a Seat Leon 5F which has the dual color ambient (white normally, and red in Cupra mode, which is equivalent to Sport in a GTI/Race in a Golf R).

I can't recall if I suspected the BCM had two light channels (pins at the connector) dedicated to those lights... Or if those lights were connected to two specific pins on the BCM that could have their polarity switched. My gut tells me it's the former because it would be unusual for the ground for lighting to go back to the BCM, normally lighting grounds are chassis. So you would have an LED module with two power inputs from the VCM, which the BCM would alternately power depending on driving mode. And of course a ground like always.

Two color LED modules being cheaper than RGB I thought about it but if my recollection is correct running two wires from the BCM into the doors is the same number of wires required to go full RGB anyway.

Long post is long, but I think Mr-Fix is doing something custom to replicate an OEM function. The other thing to consider is that the LEDs being talked about in this thread are connected to the door control module. I believe the dual color ones are connected to the BCM.

 

[jaypoto]

Fun fact about that LED in particular.. it can be red or white depending on the polarity. It sounds crazy but take a look:

That’s probably why you saw it light up red even though it was supposed to be an Alltrack door.

That's funny I actually have heard that in the past on this forum but I didn't even think to reverse it before I messed them up. Oh well, my fix worked as intended other than having to adjust the location of the led to eliminate the little hot spot. That should be pretty easy to do when I get around to it.

 

[Cuzoe]

I totally missed that you had powered up the first LED picked up and that illuminated Red . Not that it matters for you since your problem is solved... but I now want to see the wiring for a car that can use both the white/red function of that light, gotta do some digging (wasting of my time, haha).