Main beam problem

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expat2000

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Hi all

Having some problems with main beam, I think I know the solution but want to run it past you all in case I am missing something.
First off car is a 1998 A4 TDi pre-facelift but fitted with facelift headlamps (done by previous owner)

Noticed last week that when I put main beam on I get nothing from the front at all. Dips go out (as per pre-facelift spec) but no mains. Yesterday morning check voltages and getting 0.25 to 0.3V at both main beam feeds. Checked the fusebox and getting same voltages on the feed side of the fuses. Connected the bulbs +ve direct to battery and bulbs working fine. Connected battery direct to feed side of fuses and mains come just as they should.

Examining the wiring diagram (Haynes) seems the only failure point that would affect both left and right lamps is in the switch itself. Started to pull steering column shroud off but it seems that to get to the switch I need to pull the steering wheel and airbag off. Haynes says this is so as well.

Gave up at that point as needed to fit my winter tyres (first snow last week) and weather was threatening to get wet.

So now need some advice/reassurance on attacking the column switch. Is it necessary to remove the wheel/airbag to clean/inspect/replace or is there a shortcut? Cant even seem to remove the lower shroud as it goes all the way round the column. Have it loose but cant remove it to get accesss. Am I missing something else obvious?

Also Haynes doesn't show any relays? Are there really 20Amps going through the switch? Is there a single relay for the mains that I am missing?

Toying with the idea of putting another switch on the dash to cross connect the dip feed to main beam feed so I dont have to use the stalk switch at all. Would also mean that dips would stay on at the same time as mains.

Any help greatly appreciated.

Stuart
 
More likely the fl headlamps are incorrectly wired. The early pfl cars were wired so the dip went out when hi came on as they were h4 bulbs. There is a link wire to put in to enable that iirc. However it does seem like your switch isn't powering them up. Can you drop the lower column shroud and power there . You'll know if hi/lo switch causing it then and can replace according. Oh it's a steering wheel off job for lower bit. Just disconnect battery before playing and you'll be on however if you put ign on with airbag disconnected you'll put the light on and will need to clear the code to put the light out
 
You need to move the wire from pin 10 to pin 8 on the stalk to keep the low beam on when the high beam is engaged.
 
Broken Byzan said:
More likely the fl headlamps are incorrectly wired. The early pfl cars were wired so the dip went out when hi came on as they were h4 bulbs. There is a link wire to put in to enable that iirc. However it does seem like your switch isn't powering them up. Can you drop the lower column shroud and power there . You'll know if hi/lo switch causing it then and can replace according. Oh it's a steering wheel off job for lower bit. Just disconnect battery before playing and you'll be on however if you put ign on with airbag disconnected you'll put the light on and will need to clear the code to put the light out
Click to expand...

Sorry, but I think I might not have been clear. The facelift headlamps have been fitted for years, not done by me but by previous owner (one of). Up until last week the headlamp switch worked fine (in the pre-facelift configuration, dip and main exclusive) and had no problems with it. I am sure the wiring to the lamps is correct as I have continuity between the fusebox and the appropriate connectors on the lamps. Its the feed to the fusebox which is duff which is why I think the switch is faulty. Is this a likely/possible/probable fault?

Thanks for the details about getting the wheel and shroud off. I think even checking for power at the switch is going to be an issue without taking the wheel off which I was hoping not to have to do.

I think I might just fit an extra switch to the left side of the steering column so main can be switched on without using the stalk as this will be the simplest and quickest solution. Looked through the MOT regulations (which our EU-kontrol is based on) and cant see anything which says the dip/main switch has to be on the control stalk.

If I do pull it apart to clean/repair then I'll probably do the dip/main cross connect at the time.

Cheers
 
Switch then. Surely it's no more work to pop wheel off and change stalk than fiddle about accessing wires under the dash
 
Broken Byzan said:
Switch then. Surely it's no more work to pop wheel off and change stalk than fiddle about accessing wires under the dash
Click to expand...

Hmmm, you might be right but just been doing some digging and apparently the switch failing is not unknown due to the relayless system that Audi used, hefty current through a not so hefty switch leads to warpage of the plastic and lack of electrical contact. If I do get it apart and find the switch is ****** (literally) then I'm looking at a replacement one and to be honest the cost of spares over here is high. The 2nd hand spares market is non-existent. Just looked on ebay and I can get a new one (pattern) one from Poland for £25 but then add import duty and 'handling charge' at the post office I am looking at near £45. Compare that to a £3 switch from an auto electrical store and I think a simple wiring job behind the fusebox which is easier/cheaper then.

Saying that I might rethink as just realised I am going to be putting nearly 20A through the dip switch rather than its normal 10A. More thought required I think :)
 
I've never heard of a switch failing in the n years i've been on this forum, its certainly not common enough to start hacking up the dash.

Just replace the switch, and move pin 10 to pin 8 while its apart and you'll sort it all out in one go.

I presume your abroad somewhere? I might have a stalk in the garage, what type of steering wheel is fitted to your car?
 
Broken Byzan said:
Many UK sellers will send abroad without issue. Where are you?
Click to expand...

Norway. Believe me, mail order parts are my best friend, car parts are typically 4-10 times UK prices

I looked on ebay for used ones but I have cruise control so need the stalk with that as well as the headlight control and couldn't see any apart from the new pattern one from Poland.
Typical price seems about £20-£30 for used ones as well, without cruise.

The trouble I have is anything over £20 gets hit with import duty as we are outside the EU, thats 25% plus a £15 handling charge. (which is why weekend trips to UK on RyanAir usually end up with half a suitcase full of car parts! Have you ever tried to get a car radiator on as carry-on luggage? Can be done and almost worth it watching them try to find a reason why it cant.)

It's not an urgent problem as most of my driving is on lit roads but the nights are long here in the winter so I might just do the quick fix for now and see about a proper fix next year when I'll be in the UK and I can hit some old school scrap yards. Need replacement doors all round so planning to bring the car over for my summer break.

aragorn said:
I've never heard of a switch failing in the n years i've been on this forum, its certainly not common enough to start hacking up the dash.

Just replace the switch, and move pin 10 to pin 8 while its apart and you'll sort it all out in one go.

I presume your abroad somewhere? I might have a stalk in the garage, what type of steering wheel is fitted to your car?
Click to expand...

If you have a spare that would be great, not sure I know what you mean by type of steering wheel? It's round :)

It doesn't have any stereo controls if thats what you mean? I can provide some pictures later today if thats any use.

Cheers for all the advice though.

Stuart
 
There are two styles of wheel, they changed around 97/98ish. The later style has a circular band in the middle, which is sort of stimpled with lots of tiny dots. Photo would be useful.

The stalks changed at the same time (as did the steering column), so identifying the style of wheel makes it easier to identify the type of stalk you need.

If your looking on ebay, your better searching for A6 or A8 parts if you want a cruise stalk, but i can get you the part number and you can search for that instead.

The spare stalk i'll have if its still there wont be a cruise one, though you can swap the handle over fairly easily.
 
As for the radiator, my brother put a front mount intercooler in his suitcase on the way back from the USA last time he came home, had no trouble with it at all :p
 
aragorn said:
There are two styles of wheel, they changed around 97/98ish. The later style has a circular band in the middle, which is sort of stimpled with lots of tiny dots. Photo would be useful.

The stalks changed at the same time (as did the steering column), so identifying the style of wheel makes it easier to identify the type of stalk you need.

If your looking on ebay, your better searching for A6 or A8 parts if you want a cruise stalk, but i can get you the part number and you can search for that instead.

The spare stalk i'll have if its still there wont be a cruise one, though you can swap the handle over fairly easily.
Click to expand...

Pictures as requested:

IMG_20141020_190202_zpswyejzfuy.jpg




 
Last edited:
[QUOTE="aragorn, post: 2292027, member: 3141OK but ]As for the radiator, my brother put a front mount intercooler in his suitcase on the way back from the USA last time he came home, had no trouble with it at all :p[/QUOTE]

I think putting in my case would have been ok but i was travelling on the cheap so was carrying as cabin baggage!
 
OK thats the earlier wheel.

I did have an earlier stalk, i'll have a dig in the garage to see if its still there.
 
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OK update on the problem.

Due to having to work outside and the wettest October on record and my auto box problems (see my other thread) I only just got to look at the headlamp problem again.

Decided against disturbing the airbag, steering wheel to find the exact source of the problem and, as I had a spare switch and relay combo sitting in my spares box, decided to mount a replacement main switch on the left side of the lower dash. This is just below where the dip switch is so cant see any usability problems. It's also really cold and doing it this way meant I could do most of the work sitting in my kitchen.

Took a feed from the dip switch to fusebox feed through a switch and relay to the main beam fuses. So now when the dip is on the main can be switched on via the switch.
This is actually nicer than original as main does not disable the dips, all four lamps come on (as I have facelift lamps not the originals). Relaying the main beam feed means that there is no extra load on the dip switch contacts. In addition as I am feeding the relay output to the feed side of the main beam fuses I still have a fuse in the circuits and the tell tale on the dashboard works. Overall the setup is easy to use and has solved the problem so it'll be staying like that unless I have any other steering column switch problems.

I'll pop some photos on when I get some daylight (not that there is much to see now just an extra switch on the dash).
Thanks for all the offers of help.
Stuart
 
Photos as promised:




Switch is perhaps a bit OTT as its rated at 50A but is only switching 0.3A through the relay but it was the nicest I had and mouldable to the curved dash location.

Anyway it works which is the main thing.

Stuart
 
Hi all, I have now same problem with my main beam. And it's not the stalk/switch as I have checked that already. It does look like there's no 12v coming to the switch or fuses after I turn on the ignition. Everything else works just fine as it should be.
IMG_0497.JPG

Does anyone have diagram of which of these pins gets 12v after ignition is switched on? or which cable it is in the connector?

Update: I get 12v in fuse box when lights and the ignition are one. But there's no 12v in the headlight/bulb connector, any ideas where I need to check next?

Any help is appreciated.
 
Last edited:
The main beam gets two different supplies at the switch. One from the "dip beam" and one from an ignition live, which allows you to flsah with the lights off.

If neither work, i cant see how its a supply issue?
 
Sorry, I confused my self, after reading thread yesterday night I thought we're talking about low/dip beam (should have read this again in the morning before posting here).

So I have no low beam (high beam, side lights indicators etc works fine). And there's 12v in the fuses 20 and 21 after ignition and lights are on. But nothing at the connectors.
 
does high beam work if you switch low beam on, then push the stalk backwards?

I'm pretty sure the fuses are AFTER the switch, so if theres power at the fuses, the switch is fine?
 
audi upgrades
I dont think its a switch issue then.

If you push the stalk backwards to latch long beam on (rather than pulling it forward to flash the lights), it sources its power from the dip beam switch. So if the switch was broken high beam wouldnt come on if you pushed the stalk backwards.

Maybe a fault with the bulb monitoring unit? After the fusebox thats the only other single point where the signals are together.
 
Actually thinking about it, it could still be a fault in the stalk, as the flasher contacts might send the power out to the dip beam.

But, if the dip beam fuses have power, the stalk is fine, as the fuses are after the switch...
 
We had a switch just fail and drop dip. Had to drive home on fogs and occasional hi beam. It was er interesting

Sent from my SM-G935F using Tapatalk
 
Thank you for helping me out, I have used public transport last week, so have not looked at sorting low beam problem. But needs to be sorted by next week.

Aragorn - where would I find bulb monitoring unit?

Sent from my ASUS_T00G using Tapatalk
 
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