I recently installed Hella Air horns on my CLK. The horns worked fine for three days, then all of a sudden nothing! At first I thought I might have mounted the air compressor somewhere that was too hot, and thought that is what was wrong. To check if it was the air horn itself or something electrical, I connected the stock horns back. After connecting the stocks, I tested the horn, and still nothing. When I press the steering wheel down, I hear a clicking sound coming from the fuse box, so I look in there to see if the fuse is burnt. Looking at the chart I couldn't find a fuse for the horn. Any suggestions on what to do, or does someone know which fuse is for the horn on the CLK.

Thanks.

I belive that you will have to run an independent circuit with an in line fuse to your air horn. I am not sure but I think that your horn circuit is a ground interupt which won't work for your air horn compressor.I had a semi type air horn on my Air Stream motor home and it pulled quiet a bit of current, I would recomend that you go to a good auto electrical shop and not take a chanch of a melt down....
William Rogers......

Heed William's advice, take it to a pro who knows the circuit of your Mercedes.

Air horns need to be run of a relay due to their heavy current draw; your existing horn-circuit acting as the control circuit.

Have your pro set it up that way as well.

Good luck,
:-) neil

Thanks for the advice.

The horn system isn't complicated...I suspect you have merely blown a fuse if you wired the compressor directly to the leads off the factory horns.

As posted earlier, the compressor is a heavy current draw, and the kit normally would have supplied a relay.

I have a Hella air horn kit in my VW, and with a 45-amp alternator, there is not a lot of juice available for high-current accessories. With the relay, everything works fine.

You can use the factory horn leads as a switch and ground for the relay, then splice a high-current lead for the compressor to power up. The current draw for the compressor is less than 16 amps (that's the highest current that can pass through my VW fuse box), so make sure you put an inline 15-amp fuse as well.

You may have noticed that your horn takes a bit longer to blast, since there is a lag time for the compressor to spool up?

Oh yeah, another tip...angle the trumpets slightly downward to allow any moisture to drain out. Otherwise, dirt and water will get collected and trapped in the diaphrams, rendering a short life for them.

__________________
2009 ML350 (106K) - Family vehicle
2001 CLK430 Cabriolet (80K) - Wife's car
2005 BMW 645CI (138K) - My daily driver
2016 Mustang (32K) - Daughter's car

Thanks G-Benz, however since even my stock horn doesn't work right now, and I can't figure out which fuse is for the horn, I think I'm just going to take it to a professional to install the horn and fix the problem. Thanks again.