Bosch horn wiring

Jahreason

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Hi guys i am new to the forum. I Bought a pair of old school Bosch horns that came on the Mercedes Benz and the seller sent it with what appears to be a 4 pole starter solenoid 2 large poles and 2 small. My question is can this be used or do I need a regular 4 pin relay?
 
Wov.. I once had a Mercedes Horn .But there was nothing strange with that . + and - and switch button Pretty certain I remember right.
tututututut It was Autobahn Loud..
Gave the horn to a Friend that within the Month had scrapped the car with the horn still in it . That is for helping.

I Reckon this is a more modern thing please give more info.Type .Sitting on what car. Specs and or pictures
Bosch is good stuff usually .. I don't know of any better brand.
Suprising if it needs a relay but there are of Course different ones And can be from a long Haul truck even
 
Wov.. I once had a Mercedes Horn .But there was nothing strange with that . + and - and switch button Pretty certain I remember right.
tututututut It was Autobahn Loud..
Gave the horn to a Friend that within the Month had scrapped the car with the horn still in it . That is for helping.

I Reckon this is a more modern thing please give more info.Type .Sitting on what car. Specs and or pictures
Bosch is good stuff usually .. I don't know of any better brand.
Suprising if it needs a relay but there are of Course different ones And can be from a long Haul truck even

Wov.. I once had a Mercedes Horn .But there was nothing strange with that . + and - and switch button Pretty certain I remember right.
tututututut It was Autobahn Loud..
Gave the horn to a Friend that within the Month had scrapped the car with the horn still in it . That is for helping.

I Reckon this is a more modern thing please give more info.Type .Sitting on what car. Specs and or pictures
Bosch is good stuff usually .. I don't know of any better brand.
Suprising if it needs a relay but there are of Course different ones And can be from a long Haul truck even
 
Screenshot_20220412-140039_Mercari.jpg
 
Horn with a relay similar to this. It's going to be installed on a hino truck should I use this solenoid or a regular relay
 
I am no expert .But Bosch parts can have a code at the pins
Please look at the red numbers inside the square below

That code list can be found on line please google or give the numbers here

Like that Please check if it can apply to your parts and the electrical system minus ground

in the picture 30 is 12 V in and 87 out from relay to + on horn
85 and 86 is the Horn wire regulating ON / OFF signal

In Swedish 85 is out 86 is in

1649789119161.png



1649788478189.png
 
Well if the solenoid in post # 5 is being used it as it seems only have 4 posts
2 large is for Power circuit and 2 smaller is for On / Off circuit ( The horn button )
The relay works as a switch for the bigger current
It should work if there is 2 wires from the down side post -- 1 to respective horn .
But for me it is impossible to know without having it here
or knowing the electrical specs or numbering.
If the solenoid is to small -- not able to cope with the current the sum of two horns
Then it can fry .. Having said that a starter solenoid is probably big in comparison to 2 horns.
but this is guessing again without the specs.
 
Run a hot wire from the battery with an inline fuse appropriate for the horn(s) to pin 30 of the relay.
Run pin 87 to the horn(s).
Run power from the (existing) horn "fuse" to pin 85.
Run pin 86 to the (existing) horn button.

Note: This assumes it's a horn system where the button provides a ground. Keep in mind not all systems work this way. Some run power to the button and that's fed (switched) to the horn. If that's the case, just run pin 85 to ground instead of as drawn below.


Horn.png
 
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