I own a '90 300ce and just installed a new battery. I noticed a buzzing noise coming from the fuse box when the engine is turned off, but not when the engine is running. The relay that is making the noise is way back behind the fuses, it is the center one which is white in colour. I pulled it and put in a new one but it still makes noise so I just have left it off so it will not wear the battery down. I am not sure what the function is but I have noticed that when the engine is off the seats cannot be moved unless the key is turned on. Any suggestions what to do?

Sounds like you have a problem with the "comfort" relay that allows the seat operation w/key-off but door open. I would say that the relay is translucent rather than white.

You're right it is more translucent than white, but I replaced it and it was still clicking, so I just left it off. Now what?
Thanks