after market stereo installation 88 t-bird

i am currently trying to put a new head unit in my 88 t-bird it has premium sound system with an equilizer I bought the wiring harness from circuit city they also have a bypass harness. do i need to bypass the amp i cannot get any power to the radio any suggestions i am stumped.

Use the bypass harness.

Yeha use the bypass harness becuase the factory distorts the sound SOOO much its only honna cuase you more grief and possibly money (by blowing a speaker). Most modern day head units pu out more power than those amps did.