1990 S4
Fortunately just around the corner (100m) from my house tonight (yes it is dark here in NZ) I lost all main headlight function (low & main beam both sides). Headlights remained up and fog and driving lights still operated.

Checked fuses (1 - 4) and power available to several pins on relay block.

While I get my usual 928 supplier to send me a new relay from the other side of the world is someone able to give me any ideas on how to test the existing relay?

I have the cover off and nothing is obviously exploded. I do not, however, understand how the relay works or the wiring diagram on the outside of the relay. Lots of relay switches and electronic components inside.

Your assistance please.

Myles

 

if you pull up up on the stalk do the hi beams come on?
if so then the multi function switch has failed......
BUT first get some spray cleaner and put a towel under the switch and work a small amount into the headlight hi low switch portion

 

Thanks Mrmerlin.
Switch on steering column switches fog lights on when in dip position , driving lights on when in high beam position and also when in flash postion. Both indicators also appear to work correctly.

So this means that the swicth has failed if I understand you correctly.

Now where did I put that spare.............?????????????

I have a relay shipping out to me anyway (good insurance).

Myles

 

But your headlights aren't on in either dip or main beam position ? If so, and your driving lights come on in the high beam setting, sounds like it isn't the switch...

 

I had the cover off the relay to see if there was anything obvious. (there wasn't).

I put the cover back on, plugged the relay back in and turned on the lights - nothing. As I persisted with flicking the switch, everything suddenly started to work again.

Now I am really confused (and faced with trying to solve an issue that, for the moment at least, no longer exists).

Did the relay suddenly start working again or did playing with the switch fix it??????

Myles

 

follow the advice on cleaning the switch it may be dirty
I have seen this a few times no headlights will work but pulling the stalk back will run the hi beams some times you get lucky with some elex cleaner and the switch works as do the lights

 

Thanks for the advice.
I will clean the switch and report back on what I find.

Myles

 

any update on this? I'm having the exact same problem right now.

 

James,
I looked into cleaning the switch but it looked like it needed dis-assembled (again) to do properly. I had pulled it apart several years ago to fix the pawl on the indicator cancel).
I had no problems again with the switch or original relay until the main lights suddenly turned themselves off about 2hrs into a trip. (1st time it happened was after 10 minutes) Interestingly the aux / fog lights remained on when the driving lights (only high beam left) were on so it was still driveable.
The lights came back on by themselves about half an hour later. No problems for the remaining hour of the trip.

When I got home I took out the original relay and it rattled. I opened it up and found a loose piece of what looked like electronic component leg (about 3mm long) sitting in the case. I had not noticed it there when I opened up the relay before and could not see where it had come from. My guess is that it was sitting across something causing a short.

I put in my new relay and have only driven the car a couple of times at night with no futher issues.

I do not believe that the switch was the cause.

Hope this helps.
Myles