It gets cold and the light doesn’t want any more?!

Moin Moin, In February next year I am in possession of my 924 from 1982 and I love this car above all else. I have been able to learn a lot about it, through literature, try out or the Internet. But sometimes I also stood in front of the car and could only scratch my head. And now it’s time for me to not know any more. To the problem: you notice now the last two weeks that it will be autumn. Accordingly, it is also much cooler in the morning than during the day. If I now, Just like this morning also, get into my car and the temperatures below, fall about 10°C, does not go in the first 3-5 min the dipped light. I say I leave the engine on, want to go off, turn on the light, lights open, but it remains dark. The main light goes perfectly, the floor light in the auxiliary lights also shines as usual. Rear light is also everything as it should be. When I operate the main light, the dipped light sometimes stays on for a few seconds and g Is there a flicker then? Or it’s half a minute left, I’m going to go and then it’s gone again… Constant with driving light through the city until the engine is lukewarm, I don’t want to, because I hate it myself when someone comes to me with full lighting. Does anyone know this problem? Maybe from another vehicle from that time and how to solve it? The voltage indicator in the interior always shows me something between 12 & 13 V. The car battery Nagel is new, because I replaced it about two months ago. I would be very happy about a helpful post or thought suggestions! A good start to the day, DK