My right brakelight is not working even after a bulb change

Check and replace the fuses. There is often more than one fuse box, check your manual. On some cars there is a set of fuses under the hood and another inside the dashboard or under it somewhere.

Check the most obvious things first…

Bulb, guarantee that its a known good one..

Corrosion on the bulb socket

Corrosion on the light bulb support wire connector

Fuses

Check the ground connection

if all fails, you are looking at wiring problem…

One of the things that could cause this is using single filament bulbs were 2 filament bulbs are meant to be installed. to check this, remove the bulb and check the back of the bulb, count the connector pins. now check the socket and count the connector pins. these should be the same, if not you have the wrong bulb.

Might be worth checking this.

Installing wrong number of filament bulbs can cause al sort of strange behaviour, like when indicating the brake light starts flashing for example.

Try to translate this what I write. I can better tell you how to do it in German. Unter dem Lichtschalter für das Abblendlicht und Standlicht gibt es zwei Gründe Quadrate die man drücken muss. Danach gibt es eine offene Stellen zum raus ziehen. Dort findest du die Sicherungen. Auf der Abdeckung ist Nummeriert welcher Stecker für was ist. Es kann sein das eine Sicherung bei dir durchgebrannt ist. Das war bei mir der Fall.