Escort ’92 indicator

Heyho, I’m new, and the car, which now stands at my door “also”. So history: I live in Kassel and bought myself a Ford Escort with EZ ’92 in Fulda. In the TÜV report you can see that he had problems with the turn signal, but they were fixed. Also during the test drive everything went supi. Now I picked it up today, drove home and on the highway then the turn signaler went no more and you heard an easy “surrender” (if you can say so O.o). But if I the other lights all go.. can I test it again for the sake of necessity 😛 I called the seller (He has a workshop) and he said I should unscrew the cover under the steering wheel, but there I see nothing… and with the safety box in the slot, where the safety for the turn signals should be I can also not recognize any mistake.. Does one of you have an idea, what this is about and whether I can do this as an escort newcomer there myself something Or should you rather go to the workshop with it? Greetings