Horn and open door seat adjustments quit!
 

Took the 300 E for a trip to town today and noticed that the seat memory with the door open, ignition off, and the horn didn't function. I could probably do a search, but honestly, I'm just too tired (or lazy). Any clues??

door switch working?
 

1st thought would be door switch. is the interior light on with open door? - benton

Switch is ok. The interior lamps work as they should. All the fuses in the fusebox are also good.

I've read many times that the fuses can look good even when they are bad.

Do you know if it is the same fuse that affects all the troubles you are having?

I can't find any connection of the horn to the seat adjustment in my manual. I checked each fuse with an ohmeter and they were solid.

Hmmm, how about a priest? Or a rabbi?

When I took my Mercedes to the dealer after I bought it, the technician looked at my list of complaints and declared, "Your car doesn't need a technician. It needs an exorcism!"

I felt like Charlie Brown in the Halloween special. After trick or treating, the gang compare what they got. One says "I got an apple", another "I got a candy bar", and Charlie Brown says, "I got a rock!"

The moral of the story is - you need a sense of humor with these cars.

Check the diode in the fuse/relay panel. It can be defective and cause that kind of problem. It's a plug in diode similar to a fuse

I thinking along that same line.
 

Trouble is, I don't know which one it is!!

FOUND IT!!!!
 

The function relays 'A' and 'F' were reversed. They are not interchangeable. Seat function is back. Although There is no mention in the relay code section of the CD, it does also control the horn.