Horn relay location?
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Junior Member
Joined: Apr 2025
Posts: 21
Likes: 7
From: Adelaide - Australia
2017 E43 AMG Wagon - Japan Import
Horn relay location?
After having people cutting me off and idiots on ebikes/scooters, I'm thinking I want/need louder horn/s.
I'm not talking "train horn" stupid, just just another std horn (or 2) alongside the stock originals.
Have looked for fuse names and at basic wiring diagrams, I don't see anything for horn relay, is there one on my 2017 E43, if so where?
Would the easiest thing to do be to piggy back of the existing horn or use that signal to activate a relay connected to 12v so not to overload the system?
I'm not talking "train horn" stupid, just just another std horn (or 2) alongside the stock originals.
Have looked for fuse names and at basic wiring diagrams, I don't see anything for horn relay, is there one on my 2017 E43, if so where?
Would the easiest thing to do be to piggy back of the existing horn or use that signal to activate a relay connected to 12v so not to overload the system?
Last edited by LumpyCam; Apr 2, 2026 at 09:15 PM.
Out Of Control!!




Joined: Apr 2019
Posts: 12,058
Likes: 6,856
From: Silicon Valley
W212 MY'14 M276-3.5NA @75kMi
After having people cutting me off and idiots on ebikes/scooters, I'm thinking I want/need louder horn/s.
I'm not talking "train horn" stupid, just just another std horn (or 2) alongside the stock originals.
Have looked for fuse names and at basic wiring diagrams, I don't see anything for horn relay, is there one on my 2017 E43, if so where?
Would the easiest thing to do be...:
to piggy back of the existing horn
or use that signal to activate a relay connected to 12v so not to overload the system?
I'm not talking "train horn" stupid, just just another std horn (or 2) alongside the stock originals.
Have looked for fuse names and at basic wiring diagrams, I don't see anything for horn relay, is there one on my 2017 E43, if so where?
Would the easiest thing to do be...:
to piggy back of the existing horn
or use that signal to activate a relay connected to 12v so not to overload the system?
It maybe more effective to wire a dashcam for insurance purposes.
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Joined: May 2012
Posts: 2,360
Likes: 1,555
From: Pepper Pike Ohio
24 GLS580 '23 E450 4matic 12 E350 4Matic
I believe you can get higher decibel horns from places like JC WHITNEY, Maybe measure your horn volume then ordr two with your preferred increase in decibels?


