1986 S4 here. Head unit works fine and all but no sound comes out. I'm thinking it'd be kind of weird for all 4 speakers to be blown so maybe bad grounding? Well if someone could help me out with some more specific information I'd totally appreciate it (i dont know **** about wiring)

 

How do you know the head unit works? Because it lights up? Your head unit could have gone bad. If you can, try swapping in another one.

 

Is this the stock radio or did you just install an aftermarket radio?

 

stock

 

you might try taking it out and hooking a speaker that you know works to it and then try it. I hooked up my 4 chanel amp and 2 duel voice coil subs and stereo and 6 speakers and I have no problem. if it still dosent work check your fuses in the stereo.

 

ACDDori: how do you know the head unit works fine? I'm leaning more towards the stereo being the culprit.