my 240D 1981, USA version, has it between stick shift of the automatic gearbox and the ashtray, under the small removable little panel around the stick shift. You have to lift it up and remove it.
now, my flasher failed and the MBenz was quite expensive (in this country) So I bought a japanese for a fraction of the cost $5.00 I believe was for a toyota (they show the electric diagram on it) with 3 pins. I installed 3 "extension wires" connect it and worked ok, and that was about 6 months ago. no problem I works as if it were the original. Hope this idea helps you. Good luck