Headlights

Hi all,new to the site and 928s but I have a Strange one here.the pop up headlights on my 1989 s4 go up and down but don’t come on at all high or low beam but then the other morning in the garage I tried them again and they worked perfectly but that is the one and only time they have worked since I bought the car.I understand that the headlight circuit is quite complex so any one else had this problem or any suggestions on what could be wrong thanks

Hi, all UK cars of that era have an aftermarket (fitted by the Porsche dealer) alarm / immobiliser. It could be that you hadn't turned the immobiliser off correctly when you tried the first time as I've found that this interrupts quite a few circuits including the fan (which had my hunting round for a few hours wondering why this wasn't working!)

Thanks for the suggestion I’ll look into that but I don’t think it is that as I’ve been driving the car and it is used regularly and the headlights have never worked apart from that one and only time .the lights in the bumper work fine just not the pop ups

First place to look is the headlight relay - can you hear it clicking when you turn the dipped beams on?