Fuse Box.

[Martin 1]

Hi, only one of my horns is working, the only diagram I have is of the W209 under bonnet fusebox, but it's quite different to the A209 convertible one, I believe there are two 15 amp fuses but I need the diagram, can anybody help please ?

 

[cheddar]

I don’t have a diagram, but from working on them before I’m pretty sure there’s only one relay and one fuse. It’s one of the 15amp ones along the top if I recall correctly.
It will more than likely just be one faulty horn.

 

[markmifsud]

both horns are fed from the same relay, so as above I suspect a failed horn. you can test this by taking the feed from the horn that works and connecting that to the one that doesnt. If the horn still fails to sound then you know its deff the horn thats failed.

 

[Martin 1]

Thanks guys. This is the only pic I have of the underbonnet fusebox. Not a good one, but the red lines show two 15 amp fuses and where they go.

 

[markmifsud]

tried to delete

 

[markmifsud]

According to WIS, 43b feeds 43a but power is supplied only from 43b to the horn relay

but this suggests 43a and 43b are used
http://benzbits.com/w209/frontsam.pdf

 

[Martin 1]

God now I AM confused, your link shows 43 a & b as different ratings, 30A and 15A.

 

[Martin 1]

I've bought a pair of these > 2pc 12V 139dB Loud Snail Car Lorry Compact Supertone Horn Grille Mount Universal | eBay < for a bit of a chuckle, and I don't know whether I dare fit them ? Scroll down and it shows the ratings.

 

[markmifsud]

God now I AM confused, your link shows 43 a & b as different ratings, 30A and 15A.

No, they are both 15amp, the 30 refers to the circuit number

 

[Martin 1]

Do you think I can fit them ?

 

[Diesel Benz]

The wiring diagram explains it best.