1998 E320 Horn Not Working
 

Recently I used the horn in our 1998 E320 to scare off some geese. After a minute or so the horn stopped working, and hasn't worked since. I checked the fuse card and no fuse is listed for the horn. Also, disconnected the battery for a couple of minutes thinking that my resolve the situation ... no luck. The Owner's Manual offers no information about the horn. Any ideas how to get the horn functioning again?

I believe it is fuse 40 or 41 in the engine compartment fuse box. But, you can also check for voltage at the horn terminals. If you get 12v when the horn is pressed, then the problem is the horn itself.

Hirnbeiss, thanks for your reply. The fuse slots in the underhood fuse box are labeled 1 thru 26 ... so no 40 or 41 ... and none are identified as protecting the horn circuit. Checked the fuse box beside the headlamp switch and the fuse box under the rear seat ... none of those fuses are identified as protecting the horn circuit either. So I am stumped. Think I will contact the Service Advisor at our local MB dealer for help diagnosing the problem.

The fuses are definitely 40 and 41, listed as "fanfare" on the fuse card. According to this, it is the 10 amp fuse in the upper right of the hood box. Where is the Horn Fuse? - Mercedes-Benz Forum
Sorry, I don't have my W210 anymore so hard to check.

Even if you can't find the fuse, you can check voltage at the horn terminals - could narrow your list of culprits.

Hirnbeiss, removed the cover on the under-hood fuse box so I could see inside the rear compartment of the fuse box. On our 1998 E320 there are only relays in the rear compartment, no fuses as appear in the pictures of the 1997 E320 in the link you provided. Although our 1998 E320 fuse card lists fuses 40 and 41 for Fanfare those fuses are nowhere to be found. As I mentioned previously I have yet to call the Service Advisor at our local MB dealer for advice.

try this: standing in front of the car, look under plastic lid on the left near the
firewall. should be a quartet of blue/15a fuses there, one of which should be
for fanfare/horn

bumper sticker
 

"Horn broken, watch for finger."