I have a problem with getting volume out of my radio. Got one from salvage and still the volume was real low. I tried new speakers and still no fix. Is there a built in amp under the dash or somewhere in the car that would be interfering with the volume. I have a little volume but it wont get loud.

What type of radio do you have? If you have the Bose Gold Series, or if the original was, then each speaker has it's own individual amp. I just recently made a post about this. I ended up having to completely rewire the entire stereo system. It's not a lot of fun.