logo elektroda
logo elektroda
X
logo elektroda
Advanced Search
logo elektroda

VW Golf 4: Interior Lighting Dimmer Location & LED Strip Connection for Synchronized Dimming

Jaznbu 7326 17
Best answers

How can I connect an LED footwell strip in a VW Golf 4 so it lights with the interior lamp, dims together with it, and can also be switched on manually while driving?

Connect the LED strip to the interior lamp circuit in the headliner if you want it to come on with the cabin light and dim together with it [#17141857][#17146590] If you also want the strip to work independently while driving, feed it from a separate постоянный +12 V source through a switch, and add a rectifying diode so current does not feed back into the interior lamps [#17147154][#17147228][#17147345] One suggested wiring scheme is a 3-position switch: the middle terminal goes to the LED strip, one outer terminal goes to the dimmed interior-light line, and the other outer terminal goes to constant +12 V [#17147577][#17148387] In that setup, one position gives synchronized dimming with the cabin lights, another gives manual always-on, and a center/off position can fully disable the LEDs [#17147577][#17148387] The thread also notes that ordinary LED strips may extinguish slightly earlier than filament bulbs during dimming, but they should still dim with the cabin lighting [#17141876][#17146590]
Generated by the language model.
ADVERTISEMENT
Treść została przetłumaczona polish » english Zobacz oryginalną wersję tematu
Report a violation of the law
Reply | New topic
  • #1 17135309
    Jaznbu
    Level 8  
    Posts: 93
    Rate: 6
    Hello. Does anyone know where the dimmer of the vehicle interior lighting is located in the Golf 4?

    Or maybe I will describe what I want to achieve and there will be another solution to my problem. I want to connect the LED strip on the driver's and passenger's legs and the strip is to light up when opening the door and then dim at the same time as the cabin lighting.

    The cabin lighting dims by itself after closing the door and waiting about 25 seconds or after turning the key, so where could you connect to these LEDs to achieve such an effect?

    Once again: I open the car with the remote control and the cabin lights come on. Now I want the LED strip under my feet to glow and to dim at the same time as the cabin lighting, and now one more thing. I want to be able to turn on this LED strip with a button, for example while driving, as if something fell under your feet. Thank you all for the tips

    Btw. I thought to connect to the cables from the light in the ceiling lining, but will the dimming work then? And how in this case to make a switch which, after darkening, I can turn on such a strip
  • ADVERTISEMENT
  • Helpful post
    #2 17141857
    marco2255
    Level 12  
    Posts: 114
    Help: 7
    Rate: 31
    The LEDs will not dim, because they work hard with dimmers, in any case you have to connect to the interior lamp and insert an ordinary switch between them. If you have ordinary LED lists, they will glow gently even when the door is closed, then you will turn them off with the switch because the LEDs have a different resistance than the light bulbs.
  • Helpful post
    #3 17141876
    Anonymous
    Anonymous  
  • ADVERTISEMENT
  • #4 17146232
    Jaznbu
    Level 8  
    Posts: 93
    Rate: 6
    mn997 wrote:
    The LEDs will go out earlier than the bulbs. Regards. Because they have a specific "ignition" voltage


    How to make them turn off simultaneously? Is it possible at all? Unless I replace the bulbs from the cabin lighting with LEDs, hmm

    marco2255 wrote:
    The LEDs will not dim, because they work hard with dimmers, in any case you have to connect to the interior lamp and insert an ordinary switch between them. If you have ordinary LED lists, they will glow gently even when the door is closed, then you will turn them off with the switch because the LEDs have a different resistance than the light bulbs.


    And it is impossible to do it differently, i.e. to go out without the switch
  • Helpful post
    #5 17146590
    Anonymous
    Anonymous  
  • #6 17146824
    Jaznbu
    Level 8  
    Posts: 93
    Rate: 6
    Well, yes: I connected to the cube of the lamp in the headliner and there was a problem: 3 cables come out of the cube: brown blue and yellow green. One is probably a plus, another minus and the third I have no idea. In any case, the trial and error method I connected the led strip and it lights up normally when opening the door and dims when closed. How to do now so that when the door is closed, when the strip is off, I can light it with the ON / OFF switch? I thought then about the third cube cable, because I connected it like this: I connected the yellow green cube cable to the plus in leds, blue to the minus and everything is nice, but when I connected the third cube cable (brown) together with the blue one which is connected to the led cable the strip lights up, but all the lights in the cabin come on and I want the LEDs to glow without lighting the cabin. I attach a diagram, what did I do and it seemed to me that the switch in the closed position should close brown with blue and black? Because if I do, it's bad :( VW Golf 4: Interior Lighting Dimmer Location & LED Strip Connection for Synchronized Dimming20180403_1..358.jpg (943.68 kB)You must be logged in to download this attachment.
  • #7 17146970
    Anonymous
    Anonymous  
  • #8 17147028
    Jaznbu
    Level 8  
    Posts: 93
    Rate: 6
    mn997 wrote:
    LEdy will shine you just like the lighting. You can add a switch with a plus to the LED, with a rectifying diode as a check valve (protection against light bulbs)

    I am a complete layman and I did not understand what it was about hmm
    I thought more about whether there is an on / off switch which, for example, in the ON position will light up the leds even though the door is closed and the off switch will only light when the door is open. Something from my diagram that the ON position shortens me the BLACK and BLUE cable, and the BLACK and BROWN cable in the OFF position. There is such a thing?

    Maybe such a thing will do the trick?
    http://robotechnik.abc24.pl/?kat=55092&pro=385896#top_sklepu
  • ADVERTISEMENT
  • Helpful post
    #9 17147154
    Anonymous
    Anonymous  
  • #10 17147191
    Jaznbu
    Level 8  
    Posts: 93
    Rate: 6
    mn997 wrote:
    So that the voltage does not "go back" on the lighting lamps, you need to use a rectifying diode


    And on which section of my "diagram" this diode should be and where to buy such something
  • ADVERTISEMENT
  • #11 17147228
    Anonymous
    Anonymous  
  • #12 17147264
    Jaznbu
    Level 8  
    Posts: 93
    Rate: 6
    mn997 probably for you it's a piece of cake, so could you draw my drawing, how is it supposed to look like? I would ask you very much. Thanks in advance
  • #13 17147345
    Anonymous
    Anonymous  
  • #14 17147438
    Jaznbu
    Level 8  
    Posts: 93
    Rate: 6
    I understood it like this: VW Golf 4: Interior Lighting Dimmer Location & LED Strip Connection for Synchronized Dimming20180403_2..605.jpg (988.72 kB)You must be logged in to download this attachment.

    Well? :)
  • #15 17147449
    Anonymous
    Anonymous  
  • #16 17147520
    Jaznbu
    Level 8  
    Posts: 93
    Rate: 6
    Something like this? VW Golf 4: Interior Lighting Dimmer Location & LED Strip Connection for Synchronized Dimming20180403_2..411.jpg (889.91 kB)You must be logged in to download this attachment.

    And it will work? Because I don't know if we understand each other.
    I open the door with the remote control: the cabin illumination and LED strips under my feet are lit. I open the door and it still has to shine.

    I close the door and the cabin lighting goes dark after 20 seconds of inactivity along with the led strip or it starts to darken after turning the key in the ignition switch (because that's how the lighting of the cabin to which I plugged in goes out).

    Now let's say something fell under my feet and I want to light the switch with the strip itself, so this switch is ok in this picture together with these LEDs?
  • #17 17147577
    Jaznbu
    Level 8  
    Posts: 93
    Rate: 6
    I found such a solution. I will buy such a switch:
    VW Golf 4: Interior Lighting Dimmer Location & LED Strip Connection for Synchronized Dimming0867a41d4a...8e7f80.jpg (21.34 kB)You must be logged in to download this attachment.

    And now there: a black cable from the LEDs is put on the middle pin, a brown cable on the left pin and a blue cable on the right.
    It seems that I should get the effect I want, that is: in the position on the left wire, the LEDs shine all the time, and in the position on the right wire, the LEDs shine when the door is open and after turning the key, they darken. In addition, it is possible to completely turn off the LEDs. I guess because I don't know if I think well
  • #18 17148387
    Anonymous
    Anonymous  
Reply | New topic
Report a violation of the law

Topic summary

✨ The discussion centers around the location of the interior lighting dimmer in the VW Golf 4 and the integration of LED strips under the driver and passenger legs that synchronize with the cabin lighting. Users suggest connecting the LED strips to the interior lamp's wiring, noting that standard LEDs may not dim in sync with the bulbs due to differing resistances. Solutions include using a switch to control the LEDs independently and incorporating a rectifying diode to prevent backflow of current to the cabin lights. The conversation also covers wiring configurations and the use of a switch to allow the LEDs to be activated while driving, alongside the cabin lights' automatic dimming feature after closing the doors or turning the ignition key.
Generated by the language model.

FAQ

TL;DR: To sync footwell LEDs on a Golf 4, tap the dome‑light circuit and add a 12V manual feed with a diode—"provide +12V through the switch" to stop backfeed. This preserves fade‑out and adds a driver‑operated mode. [Elektroda, Anonymous, post #17147154]

Why it matters: This helps Mk4 Golf owners add footwell LEDs that follow factory fade while retaining a safe, convenient manual ON/OFF.

Quick Facts

Where’s the Golf 4 interior light “dimmer”—is there a module to tap?

The Mk4’s courtesy fade is built into the interior lighting circuit, not a separate module. You don’t need to find a standalone dimmer. Tap the dome‑light harness so your LED strip powers up on door open and fades on door close. [Elektroda, Jaznbu, post #17146824]

Which wires do what at the headliner lamp?

In the documented case: yellow‑green fed the LED positive, blue served as the dimming return (negative), and tying brown to blue backfed the cabin lights. Verify with a multimeter before final connections, as looms can vary. [Elektroda, Jaznbu, post #17146824]

Will LED strips actually dim with the Golf’s fade‑out?

Yes. When wired to the dome‑light circuit, LED strips follow the OEM fade. As one installer put it, “The LEDs will also dim.” Match polarity during testing to confirm the effect. [Elektroda, Anonymous, post #17146590]

Why do my LEDs switch off earlier than bulbs during dimming?

LEDs need a minimum forward voltage to conduct. As the fade lowers voltage, the LED goes dark once below that threshold. “The LEDs will go out earlier than the bulbs… because they have a specific ‘ignition’ voltage.” [Elektroda, Anonymous, post #17141876]

How do I wire the strip so it fades with the cabin light?

Use the dome‑light connector.
  1. Connect LED + to the dome‑light feed used by the courtesy lamp.
  2. Connect LED − to the lamp’s dimming return/ground.
  3. Open and close a door to confirm it lights and fades. [Elektroda, Jaznbu, post #17146824]

How can I add a manual ON without lighting the whole cabin?

Feed LED + through a switch from constant or accessory +12V and place a rectifying diode in series. The diode acts like a check valve, blocking backfeed to the cabin bulbs when you switch the strip on manually. [Elektroda, Anonymous, post #17147154]

What diode rating should I choose?

Use a 5A rectifier diode for short footwell strips. It adds headroom and runs cool. “If you buy 5A… it shouldn’t even heat up.” Larger diodes, like 30A units, also work if on hand. [Elektroda, Anonymous, post #17147228]

Which way round do I install the diode?

Put the diode between the manual switch and the LED +, with the band toward the LED. If the strip does not light in manual mode, reverse the diode. Reversed orientation won’t harm anything; it just blocks current. [Elektroda, Anonymous, post #17147345]

What switch setup gives Door/Off/On control?

Use an SPDT ON‑OFF‑ON switch. Connect the center to LED +. Connect one outer terminal to the “dimmer” + from the dome light, and the other outer terminal to a constant +12V. The center position turns the strip OFF. [Elektroda, Anonymous, post #17148387]

Where should I take the manual +12V feed from?

Use the radio’s +12V supply or the cigarette lighter. Many prefer the radio feed, because removing the key cuts power even if the switch stays ON. This reduces the risk of drain. [Elektroda, Anonymous, post #17147345]

My test lit every cabin bulb—what went wrong?

You backfed the interior lighting. Tying the brown wire to the blue return made all cabin lights turn on. Fix it by using the proper dome‑light lines and isolating your manual feed with a rectifier diode. [Elektroda, Jaznbu, post #17146824]

Can I isolate both the dome‑light feed and my manual feed?

Yes. Diode‑OR the two +12V sources into LED +. Place one diode in series with the dome‑light feed and another in series with the manual +. “With two [diodes]… both the lamp and the radio will be cut off from each other.” [Elektroda, Anonymous, post #17147449]

How long does the Golf 4 cabin lamp stay on before fading?

About 25 seconds, or it fades immediately when you turn the key. This is the observed factory timing for the Mk4 Golf dome light. [Elektroda, Jaznbu, post #17135309]

Will my LED strip follow the key‑on fade if wired at the lamp?

Yes. When connected at the headliner lamp, the strip lights on unlock and dims after the doors close, following the cabin lamp’s behavior. Confirm polarity and dimming with a quick door test. [Elektroda, Jaznbu, post #17146824]
Generated by the language model.
ADVERTISEMENT