Stock radio was not working when i purchase truck, radio would turn on but no sound, standard radio not Infinity unit, no amps, no big deal i wanted more options anyways. Installed new unit today and still no sound. Chance of 4 speakers being bad is slim. Any ideas.

 

speakers wires could be cut some were or disconected at speaker I've also seen the stock speakers break behind the cone

 

That's what i was thinking also but all 4 speakers?