I need someone who knows how to find the wiring from the battery to the Radio harness. Im trying to test my speakers using an aftermarket radio because I suspect the original one is shot, but I cant get the darn thing to turn on no matter which socket I have the power wire in. My best guess is that the power wire simply isnt connected to the battery so I need to know what the whole system looks like so i can check it for disconnections. Also, I got an aftermarket horn and dont know how to install it. Couldnt find a tutorial for my specific year either.

 

have u tried looking thru a wiring diagram? power to the radio is thru the ignition switch.

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Well the wiring diagram has been moderately helpful, but just because I know how the circuit works doesn't help me find the physical line and where it leads. Especially when it goes behind the firewall. Same with the Horn. As far as I can tell, my car doesnt even have Horns. Does anyone have any pictures of an S4 NA engine bay? Preferably with the horn locations circled? Because I cant find them.

 

I found them, underneath the car between the front bumper and the radiator. Was searching all over the engine bay and couldnt find them. No wonder, it was below the car. Related note, on an NA S4, could a blown fuse cause the Radio and Horns to not receive power? The rest of the car is working and lights come on on the AC (despite the blower not going) and cigarette lighter, but the radio shows no signs of life even if i plug in an aftermarket radio that I know is working, and I dont get so much as a click from my old horns.