Dipped Beam Headlights Issue

[migle20]

Hi all,

Long time lurker, just registered to become a first time poster. Howdy

My dipped beam headlights have gone, both as DLR and as dipped beam, bizarrely at the same time but I’m at a loss as to why they have and it’s starting to aggravate me..

I’ve
- checked both bulbs, filaments look ok, I only switched in brand new ones 5 months ago
- checked fuses 39 & 59 - 10a both OK
- jumped 2 and 7 behind the dash headlight switch as shown here @ 3:14 with no joy https://youtu.be/LFScT1t7evo

Only thing I haven’t replaced is the relay. Am I right in thinking this one 449 (4a) is for the dipped beam?
https://photos.app.goo.gl/5XYbFDSPjmnxrm2A9

Any other tips or suggestions would be great as I hurtled back home on the motorway with just my sidelights tonight

TIA - migle20

[migle20]

Ooo - I drive a 2010 6R 1.4L SE Automatic

[ciclo]

If DRL and low beams don't work, the most likely cause of the failure is the light switch (or previously).

Do the same test, but this time, start the engine:
1- With a multimeter, check the voltage at T17/1.
2- With the test wire, connect T17/1 with T17/7. (check the lights)
3- With the test wire, connect T17/1 with T17/3. (check the lights)

We assume that the original headlights are 'Dual' Headlights, right?

[migle20]

Yes OEM Hella. Will check tonight when I’m back from work. Thank you

[migle20]

Thanks Ciclo,

With engine running

1 - 13v, looks good
2 - No lights
3 - No lights, but can hear the relay kicking in..

I guess T17/7 is DLR & T17/3 is the switch to dipped beam?

Have double checked the bulb filaments and no I'm not going crazy..!

[ciclo]

T17/3 is for DRL.
T17/7 is for Dipped/low beam.



Well, it doesn't seem like a failure with the light switch, nor the relay...
The problem may be in the electrical wiring including fuses 39 and 59 and ground points.

Test.
Remove one of the T10 headlight connectors, left or right (it doesn't matter). Engine ON.
- With the light switch in the '0' position, check the voltage in the T10/6 slot of the headlight connector.
- With the light switch in the 'low beam' position, check the voltage in the same T10/6 slot of the headlight connector.
- We must also check with the multimeter the continuity of the ground points in the T10/5 slots of the headlight connector and any ground point of the bodywork.

[migle20]

Evening Ciclo,

Thank you for the reply and apologies for my late response.

I've just checked the voltages as requested with engine running

T10/6 @ '0' position - 0V

T10/6 @ dipped beam - 0V

T10/5 continuity - bodywork did not ground, but did ground to battery.

Weird - both my T10/5 & T10/1 were yellow/black. https://photos.app.goo.gl/U4uCXKb41bvRNNE66

[ciclo]

Hi,

From what has been said in the thread, it seems that the problem is with the light switch, although I am not 100% sure. Try/test another light switch with the same specs/part number (for example, from a salvage yard). ... and then buy a new original one if you find out that this is the problem.

If you want, you can also swap out the original 449 relay for an aftermarket '12v micro relay' with four or five legs/pins with small holes in the legs.
The original VW 449 relays used to have a relative failure rate. The original VW 646 relays are better, but it is not the correct one for your 6R because it does not have the holes in the legs/pins.

Good luck!!

[migle20]

Apologies Ciclo,

In the cold light of day I cocked up my voltages last night.

T10/6 “0” position 12v
T10/6 dipped 10v
T10/5 continuity all good

Across both headlights - are we still looking at the switch?

[ciclo]

No, in the new conditions that you mention, everything is correct with the light switch and the electrical installation up to the headlights.

We moved the problem to the headlights.
Are you absolutely sure the bulbs, retaining clips and the other parts are correctly installed?





Check the inner wires for damage, although it is unlikely that both sides will fail at the same time.