Is there another fuse box somewhere? There is one in the car and the engine bay, but there is no horn fuse. The only thing i found was a horn relay located in the ECU, so i got another ecu and put it in, but nothing happened.
Any suggestions
Thanks

 

The horn fuse is also the brake light fuse (I think it's labeled "STOP" on the cover), it's the top left one under the circuit breaker, rated at 20A.
You should also check the horns themselves and the steering wheel button.

 

Doesnt the cpu control this? I believe the ecu controls the engine. Maybe the connectors on the steering wheel are messed up.

 

Oops, missed that...

Guru20, you did replace the CPU (behind the driver's side kick panel) and not the ECU (under the passenger's feet) right?

 

Yeah, i replaced the cpu under on the left side of the drivers feet. If i replaced the ECU, what would that do.

 

We don't need no stinking horns!
Just run over anything in your way.

 

how would one check the buttons on the stearing wheel?

 

check if your buttons click when you push them...if they do and your horns work (try with a battery) then you'll have to remove the horn relay from the cpu and resolder the white connector....15 min job and it worked for me

 

usually the horn relay in the CPU needs resoldering

 

I can’t emphasise enough how much easier this sort of troubleshooting is if you have the wiring diagrams! It’s all laid out in front of you with the wire colours, pix of the plugs and their locations, etc. download them from www.fc3s.org if you have an S4, S5 owners will have to buy.

To check the horn button, find the green wire with an orange stripe on the big 17-pin top at the top of the CPU. There should be continuity between this wire and ground when the horn button is pushed.
To check the horns, briefly put 12V to the green wire with the red stripe on the same plug (it’s next to the other wire) and the horns should sound.
If it’s not the button or the horns, it’s the relay in the CPU.

 

does anyone know where the horn is, the actual location where noise comes out...haha, sorry for the crude description

 

They are right behind the front bumper, in the middle.

You will have to take off the black plastic pieces at the top to get to them.

Fikshun