I would not replace that switch! I have not replaced one for that reason.
We carry the relay you need in the fast lane. There is even a picture of it. The price is under $40.00 retail at the dealer is over a hundred.
You put in your car, click body electrical, then multipurpose relay, then the one that does the wiper and blinkers. You will see it.
ASE CERTIFIED MASTER AUTO TECHNICIAN
MERCEDES SPECIALIST 11 YRS