This may not help you at all but on the '93 300E and 94 E320 it is in the passenger footwell, behind the right side plastic cover. Once disconnected on the '93 it did not impact the regular lights, however on the '94 it had some negative effect I just can't recall what it was, it was a friend's car.
If you have some time, visit Charlie McNally in the Finch and Dufferin area, he will give you all the info you need, pretty nice and knowledgeable guy about Benzes of all vintage (the best independent in the TO area, my humble opinion ).

Alex