Hey whip been doing car audio a while myself . Take your stereo out and get the multimeter out or test light and check your red wire / possible yellow if ur after market has a high draw current . make sure you got power test it with the same ground ur stereo uses to ensure a full cicuit if you have and have a good solid 12v at least your fine there . If you are running a mach system the amp has a remote wire to turn it on that comes on with the stereo check and make sure that is hooked up . I know that seems like alot but just trying to rule out everything cause this is electrics , also make sure radio fuse under hood is good if radio is working i would imagine it is . What i would do to find out if its your speakers or not is if you have a old speaker laying around or a tweeter , home audio speaker something portable with 2 wires take it out to you car and hook the wires coming out of the headunit speaker wires usually something like a green wire and a green and white doesnt matter what way you hook it polarity on speakers as long as power is going in somewhere it will make sound and if your test speaker has sound you know the headunit is providing a output signal to the speakers , I have seen headunits hooked up incorrectly before and end because of the wrong installation it will destroy the headunits ability to output signal on the circuit board if its a cheap headunit pick up another , I personally have a very rare expensive Alpine comp deck and I have a backup one I found that wasnt working and fixed it im very good at fixing CB'S , RADIOS ,AMPS , etc . so if its not expensive swap it out problem solved sorry for long post trying to help ya friend .
