Headlight switch fail?

[bmsamson]

After 16 years I suppose anything can fail, but with the replacement part costing more than $150 i don't want to buy if that's not the problem. I recently replaced a bulb, and then had to pull the headlight unit again to work on the frunk release cable, then after have had several times when I turn on the lights and it takes a jiggle to get them going. If I hadn't been messing with the lights I'd think switch right away, but since I have, there's always the chance that it's just not connecting properly (though I've tried pulling and replacing it a couple of times just so see if that would clear the problem -- it didn't). Has anyone else had the switch fail? Know how to test it before I purchase a replacement?

[JFP in PA]

Originally Posted by bmsamson

After 16 years I suppose anything can fail, but with the replacement part costing more than $150 i don't want to buy if that's not the problem. I recently replaced a bulb, and then had to pull the headlight unit again to work on the frunk release cable, then after have had several times when I turn on the lights and it takes a jiggle to get them going. If I hadn't been messing with the lights I'd think switch right away, but since I have, there's always the chance that it's just not connecting properly (though I've tried pulling and replacing it a couple of times just so see if that would clear the problem -- it didn't). Has anyone else had the switch fail? Know how to test it before I purchase a replacement?

Common failure. You can use the VW/Audi part as well, and it is cheaper. The Audi/VW part number is 4A0-905-849-B.

[bmsamson]

Originally Posted by JFP in PA

Common failure. You can use the VW/Audi part as well, and it is cheaper. The Audi/VW part number is 4A0-905-849-B.

Thanks JFP, I was excited when I saw that part pull up at <$50, but isn’t that ignition switch, not headlight? At least that’s the description I saw in a couple of places

[particlewave]

Pull the switch out and spray electrical contact cleaner INSIDE of it (by spraying down the gap between the shaft and body) while working the switch back and forth. Do this a few times.

If it fixes your issue, you just had carbon buildup on the switch’s internal contacts. If it doesn’t, the switch is failing mechanically and should be replaced.

One test you can do is to put a volt meter on the low beam contact in the headlight connector (with headlight removed and headlight switch on) and see if you are getting power. If not, do the same test at the fuse. If still no power, it’s the switch.
If you do have power at the connector, it’s the headlight (make sure it’s connector pins aren't bent).

Reverse right/left for the car side of the connector:

[particlewave]

Originally Posted by bmsamson

Thanks JFP, I was excited when I saw that part pull up at <$50, but isn’t that ignition switch, not headlight? At least that’s the description I saw in a couple of places

Yes, that is the ignition switch and is NOT your issue. Follow my post’s instructions.

[JFP in PA]

Originally Posted by bmsamson

Thanks JFP, I was excited when I saw that part pull up at <$50, but isn’t that ignition switch, not headlight? At least that’s the description I saw in a couple of places

You are correct, I gave you the wrong part number.

[dghii]

When (if) you pull a headlight switch apart, you'll be surprised how small the contacts are and how little pressure is applied. I pulled mine apart and cleaned contacts with erasure and a little sand paper. I tweaked the contacts as best I could for more positive contact and reinstalled. Everything worked fine but after seeing the inside, I bought a spare just in case!

[MrBen]

When I pulled mine out I went to spray the shaft as pw suggested. Mine white pieces of plastic fell out like salt out of a shaker. It rattled too. My car came from Florida where I guess the heat is hard on those. I put the new one in and all my issues went away. I even have working fog lights now which I never had before

[bmsamson]

Originally Posted by particlewave

Pull the switch out

Hi. Thanks for this. I'll start by trying the remove and spray the switch test, but I'm looking at my Bentley re removal and while most of it seems straightforward, the first step on removing the knob has me a bit confused. I'm sure it'll be clear after the first time, but as this is the first for me, I'm not entirely getting it (for the kind of money it costs for one of these things, couldn't they upgrade the image quality?!). Anyway, as you've clearly done this before hopefully you can help. It looks like they're poking something to somehow release a clip, to release the knob to reveal the locking nut and go on from there. Is there a particular place (helpfully marked by some sort of indentation on the knob?) where one inserts the tool? Are we trying to open a C shaped clip like on a lock cylinder, or just pressing against something solid that will magically release with the right pressure? Is that tool they're using something like a skinny icepick? I've nothing like that in my toolbox so would have to purchase, or maybe i can just use a long nail or drill bit if all i'm trying to do is get in there and push? I don't want to break anything, nor do i want to be futzing with it for an hour trying to get it off without breaking it.....

Thanks again!

[particlewave]

You’ll use anything small and pokey (I use a jewelers screwdriver) and stick it right into the bottom, directly behind the bottom of the knob grip.

Give me a minute and I’ll get you a picture.

[bmsamson]

Originally Posted by particlewave

(I use a jewelers screwdriver)
Give me a minute and I’ll get you a picture.

oh, i've got lots of those. thanks for the tip, and thanks in advance for the pic. i think i get it now, but more info is always helpful

[particlewave]

Sorry for the wait and the blurry pics.

Here you can see the brass tab that you need to push in: