2003 mercedes clk 320 horn malfunction horn works without pressing button

SOURCE: mercedes ML 320 1998. My horn does not work

About four things to do, first check voltage at horn with key on and button pressed. If voltage there try moving the small gap screw back and fourth a few times. If that doen't work replace horn. If no voltage check fuse and horn relay, you should be able to hear the relay click when you push the horn button, If not and fuse is ok. Switch relay out with another on on the car. If that doesn't fix it check the horn button for continuity.

SOURCE: Mercedes S320 central lock

The Key Fob needs to be syncronised to the car........Try this it works for many Mercs1....ensure the battery in the "Key Fob" is OK............Press either Lock or Unlock button for more than 1 second, the lamp on the fob will light if OK. Change battery if it does not illuminate!  2.....if battery on fob OK.......Re Syncronise the key fob to the car by:.... a brief press on either button twice and within 30 seconds turn Key to position 2 on the ignition lock 
Hope that fixes it...let me know?

SOURCE: need to find battery location: 1999 Mercedes CLK 320

Hi, The battery is located in the trunk, under the trunk mat.

SOURCE: 2002 mercedes clk 320 roof wont open

look at you fuse and realey,

SOURCE: mercedes clk 320 will not start

i have a 2000 clk320. it would not start sometimes, the engine would crank but it wont start. but after an hour or so it would start. sometime i'll get somewhere park, and come out an hour later and the engine would not start. if your having the same problem, take it to autoparts store ex: autozone or kragen. they could check your battery for free. and if its not the battery. than it could either be your fuel pump. or the crank position sensor. good luck. hopefully this help.