This may be well off beam, however......Mine is a R107, so different, But....there is a stack of relays living in behind the glovebox! If you don't get an intelligent reply and your bored, go forth and remove the glovebox, they are not hard to remove and you may find it in there. If not, you'll definately find out what other relays are hidden out of sight for future reference! There is a limit to where they can place relays and it is somewhere in the dash, unlikely it's in the centre console, or behind the instrument cluster, the Germans are not that cruel. Due to their relative size they must be supported, not dangling on wires, so tend to be mounted on inner panels within the dash. Sorry I can't be of more help.

280SL