Need help w/ ML320 horn
 

My ML320 horn does not work. I suspect a bad contact at steering wheel below the airbag (sometimes it works when pushing in different directions). Please help me by advising, how to remove the steering wheel airbag to get to the wiring for horn to check for a proper contact. The whole airbag area at chich you push to sound the horn feels somewhat loose and squeeky.
Thank you.

On the back of the steering wheel (the side that faces the dash) there are 2 holes on either side, in the bottom of these 2 holes are torx screws that are removed to detach the airbag.

Gilly

Thank you, Gilly.
One more question: Do I need to do anything to assure that that airgbag won't go off? I assume, if I don't unplug any airbag wires and concentrate on horn wiring, I should be OK?

blown horn
 

Those two holes need a T-40 to come undone. Before trying the airbag R&R that might set a code if you turn the key on while disconnected, Check out the actual horns there is one directly in front of each front wheel. They are exposed to all the road grime and water and very frequently the wires that go to them will break right off if you wiggle 'em just a bit.

Air bags
 

Air bags are actually pretty safe. Always remove the key from the ignition, try not to drop them. The steering wheel comes next, you might need two people if you dont have power tools to get the 10 mm allen screw/bolt loose.

E class (210) horns bolt right on and make it sound like a MB.

Thank you all for your help.
It had been indeed the horns, namely rusted out wiring contacts.
Got the new ones and everything is OK now.

high pitch horn cuts out when interior fan is on
 

on the 98 ml, the high pitch horn cuts out when I have the interior fan blowing. What is the connection between these two systems? Coincidence? Thanks.

Problem with ML430 Horn
 

I own a ML430 (year 1999) and my horn also stopped working. I have checked the relay to make sure that it is clicking, and the 20 amp fuse is Ok. My question is where are (is) the horn located on ML430. I see one right on the firewall next to the coolant tank, but after reading this thread , it seems that the ML has two horns. What is the location of these horns. Any help will be greatly appriecated.

The horn on the firewall is for the alarm. The other two (one on each side) can be seen by looking in the forward portion of each front wheel well. They can be easily replaced by removing one nut and plug and play the new horn wiring. I replaced mine years ago with the ML 55 horns. Really sounds like a Mercedes now. See http://www.benzworld.org/tech.html?id=277 My 2 cents. :D

Horn Replacement go Mercedes OR ---
 

I replaced my Failed 1999 ML horns in 2003 with Honda Motorcycle Horns.
I wanted them to still work in another 5 years.

oh, and I used 1985 Honda Nighthawk Horns. 22 years old still going Strong.
For you non Bikers a nighthawk is a motorcycle.