Ok, my left speaker in the door works fine but i put the same one into the left side but it didnt work so i tried new speaker wire but it still didnt work. I checked all the connections an they are just fine. what could it be?

 

Radio going south?

 

im a bit confused you said you took the left speaker and put it in the left side? if you tried new wire and still nothing then the head unit is bad

 

the head unit is pretty new, ive only had it like 6 months. Its an Alpine and it had been workin fine. i tried the speaker from the left side on the right side is what i meant.

 

try a new head unit or if you still have stock radio. try that one. hopefully you used a wiring harness adapter and didnt splice into the stock wires