What does the factory amp do in my 89 town car?

Question

and can i not use the amp bypass for my new stuff

Answer 1

The factory amp powers the speakers in your car. I don't believe there is a bypass, if you are talking about this http://www.crutchfield.com/App/Product/I... it is actually basically a line level converter, but it just attenuates the signal coming from the speaker outputs of your aftermarket radio. You can not wire directly because the input signal to the amp will be way too high. You could wire directly to the speakers and bypass the factory amps and use the built in amplifier of your new headunit.