no voltage at xenon ballast. Advice please

[mini-si]

So after changing both the ballasts for my xenon headlights along with some new bulbs, I still have the same problem!
the near side xenon not working!!

Checked the voltage down at the ballast. 0 volts.

checked fuses, all ok there.

So what else could be wrong?

Am I right in thinking it cant be the relay as the same relay controls other things within the car and everything else is working fine.

Could it be the headlight switch? if so where can I get one of these from?

cheers in advance guys

 

[Crazypete00]

if you look at the back of your lights, just under the access cover there is a plug in the center, this is the feed for the lights, are you getting power to this plug? then the power comes out of the light unit into the xenon ballast (the larger of the 3 cables) and then back into your light unit (the smaller 2 cables)

 

[mini-si]

Hi Pete,
I presume I have power at the centre plug at back of head lights as my side light is working.
This is only on the near side headlight. The drivers side is fine all working ok.
Near side, side light working ok, but no voltage at the plug which come out back of headlight to power ballast.

Drivers side 11.2 volts ( working fine )
Passengers side 0 volts ( not working )

dash displays light bulb out symbol aswell!!

 

[Crazypete00]

the big plug on the headlight may have a different pin for each of the lights, so worth checking on the working side and the non working side to see if there are any differences. this would rule out the ballast

 

[mini-si]

Will check this out tonight. But it's a brand new ballast so I'm hopping it's not that.
Would the headlight switch be at fault with one of the headlights working?
I notice there's like 12 pins on the back of the headlight switch, I'm guessing there are separate terminals for each xenon??

 

[rhinopower]

I had similar problem, had to replace headlight switch

 

[mini-si]

I had similar problem, had to replace headlight switch

where did you get your headlight switch from mate?

 

[rhinopower]

Scrap yard from a TT, paid a fiver.

 

[mini-si]

Struggling to find one of these switches. There all scrappy looking on eBay. Mines immaculate and I'm a fussy git aswell. Lol
Will a switch from a a4 or passatt fit?
Also can the rotary switch be removed from the switch surround?

 

[<tuffty/>]

Scrap yard from a TT, paid a fiver.

Mk1 TT light switch is a different shape/fitment to A3/S3

<tuffty/>

 

[rhinopower]

100% from a TT, I removed the switch itself from the fascia, and popped it straight into mine.

 

[mini-si]

Collecting one tomorrow from a 2000 s3. Is it easy enough popping the switch out of the surround?
As if it's a little tatty I'll swop it with mine as mines mint.

 

[spencetate]

http://www.audi-sport.net/xf/thread...headlight-switch-in-dash.108043/#post-1113133 thread about removal here mate

 

[<tuffty/>]

TT light switch

100% from a TT, I removed the switch itself from the fascia, and popped it straight into mine.

Don't know what TT you took it from but this is from a TT over at Bill's

vs the one in my S3

<tuffty/>

 

[rhinopower]

Tuffty. I just removed the twisty but from thr fascia. And clipped only into the s3 fascia

 

[<tuffty/>]

Makes more sense

<tuffty/>

 

[mini-si]

Right then. Little update.
So I change the headlight switch and still near side xenon not working.
What the hell is going on???
Still no voltage at the wire that feeds the xenon ballast.
What else could be the cause of this??

 

[spencetate]

where is the Ballast fed from, direct from back of HL switch? or does switch feed an And gate etc in some electronics?

EDIT: just re-read thread, noticed you have only changed the "twisty bit" so it is possible that the actual metal terminals that would route the voltage around out the back of the housing could have been at fault rather than the bit you changed, do you have a multimeter to check continuity through the switch when you move the "dial" ? 1 pin should be the 12V onto the switch then as you move the dial various pins should then output that votage. not wishing to teach you to "suck eggs" but set multimeter to Ohms, put 1 lead on the input pin and other on the other various pins 1 at a time, as you rotate the dial..you should get a very low reading of as close to zero as possible as that particular circuit is "made"... if all readings are high then the housing itself is at fault. Forgot to add test the readings with ignition off

 

[mini-si]

Anyone have a wiring diagram so that I can check what number terminal should be feeding the near side xenon and if it's switching ok.

 

[spencetate]

sometimes a small diagram is imprinted on the housing itself...

 

[mini-si]

No such diagram on my switch. Time for google me thinks.

 

[spencetate]

good luck

 

[mini-si]

All fixed now.
And what a total Norman I feel like. The two times I checked the fuses I was checking main beam.

After reading my owners manual and checking the right fuse. I found it had blown. Changed the fuse and simples!
All working now.
On the plus side at least I have nice new ballast and 5000k bulbs

 

[spencetate]

Great stuff, least all Sorted and now you are an expert on Fuses enjoy the Xenons