wozza64

Hi folks
rescued a 928 s4 from a 15 year stay in a damp garage ..
I can’t get the lights to come up electrically, I can wind them up but when I turn on the ignition they go down electrically.


is this part of the system ?
if so what is it. What does it do and is there a way of testing it ?
any advice on the matter much appreciated
thanks Warren

The Forgotten On

That is a stop gap to get DRL in some markets if I remember correctly.

Reason for them not raising could most likely be a bad headlight switch or a bad headlight relay.

Since you also said it was stored in a damp garage I would clean all the grounds and contacts in that circuit as they probably have some corrosion on them.

wozza64

Thanks “the forgotten one” I’ll have a look at those 👍

FredR

The German script suggests it is some kind of dimmer but whether it has any place on a 928 I have no idea and have not come across such for what little that is worth.

The usual suspect for the problem you describe is the headlight relay which is just one of the many parts that inevitably go south with age. Unfortunately they are not cheap items to replace at circa US$200 as I recall so useful to try and prove conclusively that is the issue. When mine went south I was fortunate enough to have a spare in my parts bin.

Petza914

With he 928 there is a way to keep the headlights up all the time when the motor fails. If the headlight switch is the last thing you turn off after shutting off the car, the lights stay raised even with them off. Then, before turning the key again, turn the headlight switch on first, then the key, and they'll stay up. This means you only have to manually crank them up once. Handy when washing the car too.